• Title/Summary/Keyword: climate model

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A Study on the Development of Automotive Climate Controller Using Fuzzy Logic (퍼지 논리를 이용한 자동차 기후제어기 개발에 관한 연구)

  • 이운근;이준웅;백광렬
    • Transactions of the Korean Society of Automotive Engineers
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    • v.8 no.5
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    • pp.196-206
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    • 2000
  • These days, the fuzzy logic or the fuzzy set theory has received attention from a number of researchers in the area of industrial application. Moreover, the fuzzy logic control has been successfully applied to a large numbers of control problems where the conventional control methods had failed. Using this control theory we designed a climate controller for an automotive climate control system whose mathematical model is difficult. This paper describes an automotive climate control where the fuzzy control has been used to stabilize parameter uncertainties and disturbance effects. To show the validity and effectiveness of the proposed control method, the fuzzy logic controller was implemented with a philips 80C552 microcomputer chip and tested in an actual vehicle. From the experimental results, it could be conduced that the proposed controller is superior to conventional controllers in both control performance and thermal comfort. The climate control system in cars is difficult to model mathematically so we tested a fuzzy logic control system which promised better results.

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Future subsurface drainage in the light of climate change in Daegu, South Korea (기후변화에 따른 대구지역 지하배수 전망)

  • Nkomozepi, Temba;Chung, Sang-Ok
    • Current Research on Agriculture and Life Sciences
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    • v.30 no.2
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    • pp.97-104
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    • 2012
  • Over the last century, drainage systems have become an integral component of agriculture. Climate observations and experiments using General circulation models suggest an intensification of the hydrologic cycle due to climate change. This study presents hydrologic simulations assessing the potential impact of climate change on subsurface drainage in Daegu, Republic of Korea. Historical and Long Ashton Research Station weather generator perturbed future climate data from 15 general circulation models for a field in Daegu were ran into a water management simulation model, DRAINMOD. The trends and variability in rainfall and Soil Excess Water ($SEW_{30}$) were assessed from 1960 to 2100. Rainfall amount and intensity were predicted to increase in the future. The predicted annual subsurface drainage flow varied from -35 to 40 % of the baseline value while the $SEW_{30}$ varied from -50 to 100%. The expected increases in subsurface drainage outflow require that more attention be given to soil and water conservation practices.

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Spatial Downscaling of Precipitation from GCMs for Assessing Climate Change over Han River and Imjin River Watersheds

  • Jang, S.;Hwang, M.;Hur, Y. T.;Yi, J.
    • International conference on construction engineering and project management
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    • 2015.10a
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    • pp.738-739
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    • 2015
  • The main objective of this study, "Spatial Downscaling of Precipitation from GCMs for Assessing Climate Change over Han River and Imjin River Watersheds", is to carry out over Han River and Imjin River watersheds. To this end, a statistical regression method with MOS (Model Output Statistics) corrections at every downscaling step was developed and applied for downscaling the spatially-coarse Global Climate Model Projections (GCMPs) from CCSM3 and CSIRO with respect to precipitation into 0.1 degree (about 11 km) spatial grid over study regions. The spatially archived hydro-climate data sets such as Willmott, GsMap and APHRODITE datasets were used for MOS corrections by means of monthly climatology between observations and downscaled values. Precipitation values downscaled in this study were validated against ground observations and then future climate simulation results on precipitation were evaluated for the projections.

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Potential Habitats and Change Prediction of Machilus thunbergii Siebold & Zucc. in Korea by Climate Change (기후변화에 따른 한반도 후박나무의 잠재 생육지 및 변화예측)

  • Yun, Jong-Hak;Nakao, Katsuhiro;Park, Chan-Ho;Lee, Byoung-Yoon
    • Korean Journal of Environment and Ecology
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    • v.25 no.6
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    • pp.903-910
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    • 2011
  • The research was carried out in order to find climate factors which determine the distribution of Machilus thunbergii, and the potential habitats under the current climate and three climate change scenario by using classification tree (CT) model. Four climate factors; the minimum temperature of the coldest month (TMC), the warmth index (WI), summer precipitation (PRS), and winter precipition (PRW) : were used as independent variables for the model. The model of distribution for Machilus thunbergii (Mth-model) constructed by CT analysis showed that minimum temperature of the coldest month (TMC) is a major climate factor in determining the distribution of M. thunbergii. The area above the $-3.3^{\circ}C$ of TMC revealed high occurrence probability of the M. thunbergii. Potential habitats was predicted $9,326km^2$ under the current climate and $61,074{\sim}67,402km^2$(South Korea: $58,419{\sim}61,137km^2$, North Korea: $2,655{\sim}6,542km^2$) under the three climate change scenarios (CCCMA-A2, CSIRO-A2, HADCM3-A2). The Potential habitats was to predicted increase by 51~56%(South Korea: 49~51%, North Korea: 2~5%) under the three climate change scenarios. The potential expand of M. thunbergii habitats has been expected that it is competitive with warm-temperate deciduous broadleaf forest. M. thunbergii is evaluated as the indicator of climate change in Korea and it is necessary for M. thunbergii to monitor of potential habitats.

An Analysis of the Effect of Climate Change on Flow in Nakdong River Basin Using Watershed-Based Model (유역기반 모형을 이용한 기후변화에 따른 낙동강 유역의 하천유량 영향 분석)

  • Shon, Tae-Seok;Lee, Sang-Do;Kim, Sang-Dan;Shin, Hyun-Suk
    • Journal of Korea Water Resources Association
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    • v.43 no.10
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    • pp.865-881
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    • 2010
  • To evaluate influence of the future climate change on water environment, it is necessary to use a rainfall-runoff model, or a basin model allowing us to simultaneously simulate water quality factors such as sediment and nutrient material. Thus, SWAT is selected as a watershed-based model and Nakdong river basin is chosen as a target basin for this study. To apply climate change scenarios as input data to SWAT, Australian model (CSIRO: Mk3.0, CSMK) and Canadian models (CCCma: CGCM3-T47, CT47) of GCMs are used. Each GCMs which have A2, B1, and A1B scenarios effectively represent the climate characteristics of the Korean peninsula. For detecting climate change in Nakdong river basin, precipitation and temperature, increasing rate of these were analyzed in each scenarios. By simulation results, flow and increasing rate of these were analyzed at particular points which are important in the object basin. Flow and variation of flow in the scenarios for present and future climate changes were compared and analyzed by years, seasons, divided into mid terms. In most of the points temperature and flow rate are increased, because climate change is expected to have a significant effect on rising water temperature and flow rate of river and lake, further on the basis of this study result should set enhancing up water control project of hydraulic structures caused by increasing outer discharge of the Nakdong River Basin due to climate change.

Ensemble Projection of Climate Suitability for Alfalfa (Medicago Sativa L.) in Hamkyongbukdo (함경북도 내 미래 알팔파 재배의 기후적합도 앙상블 전망)

  • Hyun Seung Min;Hyun Shinwoo;Kim Kwang Soo
    • Journal of The Korean Society of Grassland and Forage Science
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    • v.44 no.2
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    • pp.71-82
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    • 2024
  • It would be advantageous to grow legume forage crops in order to increase the productivity and sustainability of sloped croplands in Hamkyongbukdo. In particular, the identification of potential cultivation areas for alfalfa in the given region could aid decision-making on policies and management related to forage crop production in the future. This study aimed to analyze the climate suitability of alfalfa in Hamkyongbukdo under current and future climate conditions using the Fuzzy Union model. The climate suitability predicted by the Fuzzy Union model was compared with the actual alfalfa cultivation area in the northern United States. Climate data obtained from 11 global climate models were used as input data for calculation of climate suitability in the study region to examine the uncertainty of projections under future climate conditions. The area where the climate suitability index was greater than a threshold value (22.6) explained about 44% of the variation in actual alfalfa cultivation areas by state in the northern United States. The climatic suitability of alfalfa was projected to decrease in most areas of Hamkyongbukdo under future climate scenarios. The climatic suitability in Onseong and Gyeongwon County was analyzed to be over 88 in the current climate conditions. However, it was projected to decrease by about 66% in the given areas by the 2090s. Our study illustrated that the impact of climate change on suitable cultivation areas was highly variable when different climate data were used as inputs to the Fuzzy Union model. Still, the ensemble of the climate suitability projections for alfalfa was projected to decrease considerably due to summer depression in Hamkyongbukdo. It would be advantageous to predict suitable cultivation areas by adding soil conditions or to predict the climate suitability of other leguminous crops such as hairy vetch, which merits further studies.

A Study on the Urban Heat Simulation Model Incorporating the Climate Changes (기후변화가 반영된 도시 열환경 시뮬레이션 모델의 연구)

  • Kang, Jonghwa;Kim, Wansoo;Yun, Jeongim;Lee, Joosung;Kim, Seogcheol
    • Journal of Korean Society for Atmospheric Environment
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    • v.34 no.5
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    • pp.697-707
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    • 2018
  • A fast running model comprising the climate change effects is proposed for urban heat environment simulations so as to be used in urban heat island studies and/or the urban planning practices. By combining Hot City Model, a high resolution urban temperature prediction model utilizing the Lagrangian particle tracing technique, and the numerical weather simulation data which are constructed up to year of 2100 under the climate change scenarios, an efficient model is constructed for simulating the future urban heat environments. It is applicable to whole city as well as to a small block area of an urban region, with the computation time being relatively short, requiring the practically manageable amount of the computational resources. The heat environments of the entire metropolitan Seoul area in South Korea are investigated with the aid of the model for the present time and for the future. The results showed that the urban temperature gradually increase up to a significant level in the future. The possible effects of green roofs on the buildings are also studied, and we observe that green roofs don't lower the urban temperature efficiently while making the temperature fields become more homogeneous.

Estimation of Inflow into Namgang Dam according to Climate Change using SWAT Model (SWAT 모형을 이용한 기후변화에 따른 남강댐 유입량 추정)

  • Kim, Dong-Hyeon;Kim, Sang-Min
    • Journal of The Korean Society of Agricultural Engineers
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    • v.59 no.6
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    • pp.9-18
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    • 2017
  • The objective of this study was to estimate the climate change impact on inflow to Namgang Dam using SWAT (Soil and Water Assessment Tool) model. The SWAT model was calibrated and validated using observed flow data from 2003 to 2014 for the study watershed. The $R^2$ (Determination Coefficient), RMSE (Root Mean Square Error), NSE (Nash-Sutcliffe efficiency coefficient), and RMAE (Relative Mean Absolute Error) were used to evaluate the model performance. Calibration results showed that the annual mean inflow were within ${\pm}5%$ error compared to the observed. $R^2$ were ranged 0.61~0.87, RMSE were 1.37~7.00 mm/day, NSE were 0.47~0.83, and RMAE were 0.25~0.73 mm/day for daily runoff, respectively. Climate change scenarios were obtained from the HadGEM3-RA. The quantile mapping method was adopted to correct bias that is inherent in the climate change scenarios. Based on the climate change scenarios, calibrated SWAT model simulates the future inflow and evapotranspiration for the study watershed. The expected future inflow to Namgang dam using RCP 4.5 is increasing by 4.8 % and RCP 8.5 is increasing by 19.0 %, respectively. The expected future evapotranspiration for Namgang dam watershed using RCP 4.5 is decreasing by 6.7 % and RCP 8.5 is decreasing by 0.7 %, respectively.