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  • Title/Summary/Keyword: Regional prediction

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Prediction of Concentrations and Congener Patterns of Polychlorinated Biphenyls in Korea Using Historical Emission Data and a Multimedia Environmental Model (장기 배출량 자료와 다매체 환경모델을 이용한 국내 대기 중 PCB 농도 및 패턴 예측)

  • Choi, Sung-Deuk
    • Journal of Korean Society for Atmospheric Environment
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    • v.24 no.2
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    • pp.249-258
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    • 2008
  • Historical emission data for 11 polychlorinated biphenyls (PCBs) and a regional multimedia environmental model, CoZMo-POP 2, were used to predict air concentrations and congener patterns in Korea. The total emission value for South Korea was allocated to sub-provinces and cities based on their population. The spatial distribution of PCB emissions was generally correlated with that of measured atmospheric levels, suggesting that population could be a good surrogate for the intensity of PCB emission in Korea. The simulated time trends of air concentrations well reflected those of emission with a peak in the mid-1970s and insignificant levels in the 2030s. The model predicted that the contribution of volatile PCBs had increased after emission reduction iii the 1970s. This trend would continue until the early 2030s. The measured and modeled PCB levels in the 2000s were in an agreement of an order of magnitude, and their congener patterns were very similar. Consequently, despite of high uncertainty for emission estimates, the emission data for Korea used in this study is considered to be reliable. The results of this study could be compared with simulation data based on a new emission inventory to be developed by measurements in the near future.

Prediction of Household Ratio by Rice Farm Scale in ChungCheongnam-province - Focused on Markov Chains and Quadratic Programming - (충청남도 논 경지규모별 농가비율 예측 -마르코프체인과 이차계획법을 중심으로-)

  • Kim, Sung-Rok
    • Journal of Agricultural Extension & Community Development
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    • v.24 no.1
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    • pp.1-8
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    • 2017
  • The Purpose of this study is to predict farm size per farming household in Chungcheongnam-province by using the Markov chains and Quadratic Programming.. The results are as follows; First, small-scale farms with less than 1.0ha of land are predicted to be still more than half (of total farming households) in 2025 as well. Second, large-scale farms with 3.0ha-5.0ha land and extra large-scale farms with over 5.0ha of land are predicted to gradually expand their proportion in total farm scale. Third, middle-scale farms with 1.0ha-3.0ha land are forecasted to be reduced in their relative proportion. It is required to take into account regional characteristics to improve the effectiveness of a rice industry policy. Therefore, this study has some significance in attempting to research on the ownership structure of rice production areas in consideration of target regions.

Compatibility for the Typhoon Damages Predicted by Korea Risk Assessment Model Input Data (한국형 재해평가모형(RAM)의 초기입력자료 적합성 평가)

  • Park, Jong-Kil;Lee, Bo-Ram;Jung, Woo-Sik
    • Journal of Environmental Science International
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    • v.24 no.7
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    • pp.865-874
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    • 2015
  • This study was conducted to investigate the correlation between the distribution chart and input data of the predicted 3-second gust and damage cost, by using the forecast field and analysis field of Regional Data Assimilation Prediction System (RDAPS) as initial input data of Korea risk assessment model (RAM) developed in the preceding study. In this study the cases of typhoon Rusa which caused occurred great damage to the Korean peninsula was analyzed to assess the suitability of initial input data. As a result, this study has found out that the distribution chart from the forecast field and analysis field predicted from the point where the effect due to the typhoon began had similarity in both 3-second gust and damage cost with the course of time. As a result of examining the correlation, the 3-second gust had over 0.8, and it means that the forecast field and analysis field show similar results. This study has shown that utilizing the forecast field as initial input data of Korea RAM could suit the purpose of pre-disaster prevention.

The Prediction of Injection Distances for the Minimization of the Pressure Drop by Empirical Static Model in a Pulse Air Jet Bag Filter (충격기류식 여과집진기에서 경험모델을 이용한 최소압력손실의 분사거리 예측)

  • Suh, Jeong-Min;Park, Jeong-Ho;Lim, Woo-Taik
    • Journal of Environmental Science International
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    • v.20 no.1
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    • pp.25-34
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    • 2011
  • The new empirical static model was constructed on the basis of dimension analysis to predict the pressure drop according to the operating conditions. The empirical static model consists of the initial pressure drop term (ΔPinitial) and the dust mass number term(Ndust=ω0νfPpulset), and two parameters (dust deposit resistance and exponent of dust mass number) have been estimated from experimental data. The optimum injection distance was identified in the 64 experimental data at the fixed filtration velocity and pulse pressure. The dust deposit resistance (Kd), one of the empirical static model parameters got the minimum value at d=0.11m, at which the total pressure drop was minimized. The exponent of dust mass number was interpreted as the elasticity of pressure drop to the dust mass number. The elasticity of the unimodal behavior had also a maximum value at d=0.11m, at which the pressure drop increased most rapidly with the dust mass number. Additionally, the correlation coefficient for the new empirical static model was 0.914.

Analysis of Infiltration Area using Prediction Model of Infiltration Risk based on Geospatial Information (지형공간정보 기반의 침투위험도 예측 모델을 이용한 최적침투지역 분석)

  • Shin, Nae-Ho;Oh, Myoung-Ho;Choe, Ho-Rim;Chung, Dong-Yoon;Lee, Yong-Woong
    • Journal of the Korea Institute of Military Science and Technology
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    • v.12 no.2
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    • pp.199-205
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    • 2009
  • A simple and effective analysis method is presented for predicting the best infiltration area. Based on geospatial information, numerical estimation barometer for degree of infiltration risk has been derived. The dominant geospatial features influencing infiltration risk have been found to be area altitude, degree of surface gradient, relative direction of surface gradient to the surveillance line, degree of surface gradient repetition, regional forest information. Each feature has been numerically expressed corresponding to the degree of infiltration risk of that area. Four different detection probability maps of infiltration risk for the surveillance area are drawn on the actual map with respect to the numerically expressed five dominant factors of infiltration risks. By combining the four detection probability maps, the complete picture of thr best infiltration area has been drawn. By using the map and the analytic method the effectiveness of surveillance operation can be improved.

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

  • Ji, Hyo-Eun;Lee, Hwa-Woon;Won, Gyeong-Mee
    • Journal of Environmental Science International
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    • v.18 no.4
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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.

Optimum Macro-Siting for Offshore Wind Farm Using RDAPS Sea Wind Model (RDAPS Sea Wind Model을 이용한 해상풍력발전단지 최적 Macro-Siting)

  • Lee, K.H.;Jun, S.O.;Park, K.H.;Lee, D.H.;Park, Jong-Po
    • 한국전산유체공학회:학술대회논문집
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    • 2011.05a
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    • pp.286-290
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    • 2011
  • This paper introduces the optimum macro-siting of a potential site for an offshore wind farm around Jeju Island using the RDAPS sea wind model. The statistical model was developed by analyzing the sea wind data from RDAPS model, and the meso-scale digital wind map was prepared. To develop the high resolution spatial calibration model, Artificial Neural Network(ANN) models were used to construct the wind and bathymetric maps. Accuracy and consistency of wind/bathymetric spatial calibration models were obtained using analysis of variance. The optimization problem was defined to maximize the energy density satisfying the criteria of maximum water depth and maximum distance from the coastline. The candidate site was selected through Genetic Algorithm(GA). From the results, it is possible to predict roughly a candidate site location for the installation of the offshore wind jam, and to evaluate the wind resources of the proposed site.

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Development of Correction Method for Weather Forecast Data considering Characteristics Rainfall (강수의 특성을 고려한 기상 예측자료의 보정 기법 개발)

  • Lee, Seon-Jeong;Yoon, Seong-Sim;Bae, Deg-Hyo
    • Proceedings of the Korea Water Resources Association Conference
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    • 2011.05a
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    • pp.33-33
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    • 2011
  • 현재 우리나라 기상청에서는 단기, 중기 및 장기 예보자료를 생산하고 있으나, 이들 자료는 단순히 일기 예보에 치중되어 생산되고 있어 강우-유출해석에 직접 적용하기에는 시 공간 해상도가 크고 정량적 강수예측의 정확도가 미흡하다. 이에 기상 및 수자원분야에서는 정확도 개선을 위해서 관측강우와 예측강우의 비교 분석을 통해 편차를 산정하여 예측강수를 보정하는 기법을 적용하고 있다. 다만, 기존의 편차보정방법은 보정인자로 강수량만을 고려하기 때문에 정확도 개선에는 한계가 존재한다. 따라서 본 연구에서는 수자원분야의 수치예보자료의 정확도를 향상시키기 위해 규모, 발생영역에 대한 강수의 특성을 고려한 강수예측자료의 편차보정 방법을 제안하고 이를 강우-유출모델에 적용하여 개선정도를 평가하고자 한다. 이에 적용유역을 춘천댐상류유역으로 선정하고 국내 기상청의 RDAPS(Regional Data Assimilation and Prediction System)수치예보자료, 지점강우자료, radar자료의 수문기상자료와 지형자료를 수집하였다. 화천, 평화의 댐 일부 미계측유역의 관측자료로 radar자료를 이용하였다. 이상의 자료를 토대로 강우강도 및 규모, 영향범위를 고려한 예측강우의 편차를 산정하여 RDAPS 수치예보자료의 정확도를 개선하고 평가하였다. 이는 해당 유역뿐만 아니라 주변 유역의 정보를 이용하여 예측강우의 발생위치에 대한 오차를 고려한 방법으로, 각 영역별로 예측강우의 편차보정계수를 산정하여 적용하였다. 또한, 이전시간대의 강우 편차에 대한 오차를 줄이기 위해 정규분포방법을 이용한 Ensemble 편차보정계수를 산정하고 최근 생산된 수치예보자료에 적용하여 확률예측강우를 산정하였다.

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A Numerical Sensitivity Experiment of the Downslope Windstorm over the Yeongdong Region in Relation to the Inversion layer of Temperature (역전층이 영동 지역의 활강풍에 미치는 영향에 관한 민감도 수치실험 연구)

  • Lee, Jae Gyoo;In, So-Ra
    • Atmosphere
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    • v.19 no.4
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    • pp.331-344
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    • 2009
  • A sensitivity study has been performed using ARPS (Advanced Regional Prediction System) version 5.2.10 in a downslope windstorm case of 12-13 February 2006. The purpose of this study was to find out the role of the inversion layer of temperature mainly in relation to the strength of the downslope winds over the Yeongdong region located downstream of the Taebaek mountains. Under the conditions of N (Brunt-V¨ais¨ala frequency)=0.008 and N=0.016, the effects of the presence of the inversion layer, its variation of height of the layer, and the depth of the layer were identified. The sensitivity experiments suggested that the inversion layer effected the downstream wind speed of the mountains under both conditions of N=0.008 and N=0.016, and notably when the inversion layer was located near the mountain crest the downstream wind speed of the mountains was strong (~ 27ms1) only under the condition of N=0.016. In addition, when the atmosphere was rather stable (N=0.016) and the depth of the layer was relatively thin (765 m) the downstream wind speed of the mountains was the strongest (~ 30ms1) among the sensitivity experiments.

Characteristics and Error Analysis of Solar Resources Derived from COMS Satellite (기상청 천리안 위성 자료를 활용한 태양광 기상자원 특성 및 오차 분석)

  • Lee, Su-Hyang;Kim, Yeon-Hee
    • Atmosphere
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    • v.30 no.1
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    • pp.59-73
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    • 2020
  • The characteristics of solar resources in South Korea were analyzed by comparing the solar irradiance derived from COMS (Communication, Ocean and Meteorological Satellite) with in-situ ground observation data (Pyranometer). Satellite-derived solar irradiance and in-situ observation showed general coincidence with correlation coefficient higher than 0.9, but the satellite observations tended to overestimate the radiation amount compared to the ground observations. Analysis of hourly and monthly irradiance showed that relatively large discrepancies between the satellite and ground observations exist after sunrise and during July~August period which were mainly attributed to uncertainties in the satellite retrieval such as large atmospheric optical thickness and cloud amount. But differences between the two observations did not show distinct diurnal or seasonal cycles. Analysis of regional characteristics of solar irradiance showed that differences between satellite and in-situ observations are relatively large in metrocity such as Seoul and coastal regions due to air pollution and sea salt aerosols which act to increase the uncertainty in the satellite retrieval. It was concluded that the satellite irradiance data can be used for assessment and prediction of solar energy resources overcoming the limitation of ground observations, although it still has various sources of uncertainty.