• Title/Summary/Keyword: spatial assimilation

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A Study on Ontological Spatial Concept shown at Works of Peter Zumthor (페터 춤토르 작품에 나타난 존재론적 공간개념에 관한 연구)

  • Lee, Ok-Jae;Kim, Moon-Duck
    • Korean Institute of Interior Design Journal
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    • v.24 no.2
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    • pp.117-124
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    • 2015
  • With the modern society approaching, a lot of new paradigms have been created which can be explained by the existing space notions while suspicions on the true essence and existence of space have been raised. Ontology regards as the beginning the cause for a 'Field' which will be faced for the research of the essence of a space where 'being-in-the-world' exists. This study has analyzed the existing method of space construction in the spatial thinking and works of Peter Zumthor who mentioning ontological viewpoint as the physiological background of his works so that the ontological spatial concept may be clarified. The following is the study results. First, in order to construct the structures of his own designing into a 'Field' for experiencing the existential meaning, Zumthor chose a reductive pattern with the entire additional elements removed. The materials leading the subjects to call attention to memory and experience and the methods dealing with it enables the realization of various spatial essences. Second, the ontological event-system is required for the formation of relationship among beings. He tried to create a spatial meaning by introducing external environment into the inside and using the materials reflecting regional features and phenomenological empiricism through the multisensory experience. Third, he applied assimilation/insert/adjustment/formative change as the way of constructing the relationship between site and structure.

Adequacy evaluation of the GLDAS and GLEAM evapotranspiration by eddy covariance method (에디공분산 방법에 의한 GLDAS와 GLEAM 증발산량의 적정성 평가)

  • Lee, Yeongil;Im, Baeseok;Kim, Kiyoung;Rhee, Kyounghoon
    • Journal of Korea Water Resources Association
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    • v.53 no.10
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    • pp.889-902
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    • 2020
  • This study was performed in Seolmacheon basin to evaluate the adequacy of GLDAS (Global Land Data Assimilation System) and GLEAM (Global Land Evaporation Amsterdam Model) evapotranspiration data. The verification data necessary for the evaluation of adequacy were calculated after processing the latent heat flux data produced in the Seolmacheon basin with the Koflux program. In order to gap-fill the empty period, alternative evapotranspiration was calculated in three ways: FAO-PM (Food and Agriculture Organization-Penman Monteith), MDV (Mean Diurnal Variation) and Kalman Filter. This study selected Kalman Filter method as the data gap-filling method because it showed the best Bias and RMSE among the three methods. The amount of GLDAS spatial evapotranspiration was calculated as Noah (version 2.1) with a time interval of 3 hours and a spatial resolution of 0.25°. The amount of GLEAM spatial evapotranspiration was calculated using GLEAM (version 3.1a). This study evaluated the spatial evapotranspiration of GLDAS and GLEAM as the evapotranspiration based on eddy covariance. As a result of evaluation, GLDAS spatial evapotranspiration showed better results than GLEAM. Accordingly, in this study, the GLDAS method was proposed as a method for calculating the amount of spatial evapotranspiration in the Seolmacheon basin.

A Numerical Experiment in Assimilating Agricultural Practices in a Mixed Pixel Environment using Genetic Algorithms

  • Honda, Kyoshi;Ines, Amor V.M.
    • Proceedings of the KSRS Conference
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    • 2003.11a
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    • pp.837-839
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    • 2003
  • Low spatial resolution remote sensing (RS) data (LSRD) are promising in agricultural monitoring activities due to their high temporal resolution, but under such a spatial resolution, mixing in a pixel is a common problem. In this study, a numerical experiment was conducted to explore a mixed pixel problem in agriculture using a combined RSsimulation model SWAP (Soil-Water-Atmosphere -Plant) and a Genetic Algorithm (GA) approach. Results of the experiments showed that it is highly possible to address the mixed pixel problem with LSRD.

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Reframing Loss: Chinese Diaspora Identity in K. H. Lim's Written in Black

  • Hannah Ming Yit Ho
    • SUVANNABHUMI
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    • v.15 no.2
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    • pp.131-152
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    • 2023
  • In analyzing the Chinese diaspora, this paper explores losses that are encountered within the family in the nation. It argues that increased social and spatial mobilities that contribute to losses can be reconfigured through the productive lens of supermobility, as Laurence J. C. Ma conceptualizes it. Supermobile identities are significant avenues to consider the way that losses traditionally associated with migration and assimilation are revisited in view of new flows of migration and identification. In examining K. H. Lim's debut novel Written in Black (2014), this study addresses pathways from debilitating losses to productive losses journeyed by the family from the child's perspective. It offers a critical analysis of the Anglophone Bruneian novel in terms of its exclusive portrayal of an ethnic Chinese family. Departing from a fixed notion of home as cultural and physical rootedness, it explores flexible identities that are tied to shifting concepts of belonging. Rather than a magnification of social and spatial losses, the analysis highlights the way that the literary imagination of ethnic Chinese in Brunei Darussalam accommodates progressive ideas of the agency and advancement of the Chinese diaspora as a supermobile community.

Ensemble Downscaling of Soil Moisture Data Using BMA and ATPRK

  • Youn, Youjeong;Kim, Kwangjin;Chung, Chu-Yong;Park, No-Wook;Lee, Yangwon
    • Korean Journal of Remote Sensing
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    • v.36 no.4
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    • pp.587-607
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    • 2020
  • Soil moisture is essential information for meteorological and hydrological analyses. To date, many efforts have been made to achieve the two goals for soil moisture data, i.e., the improvement of accuracy and resolution, which is very challenging. We presented an ensemble downscaling method for quality improvement of gridded soil moisture data in terms of the accuracy and the spatial resolution by the integration of BMA (Bayesian model averaging) and ATPRK (area-to-point regression kriging). In the experiments, the BMA ensemble showed a 22% better accuracy than the data sets from ESA CCI (European Space Agency-Climate Change Initiative), ERA5 (ECMWF Reanalysis 5), and GLDAS (Global Land Data Assimilation System) in terms of RMSE (root mean square error). Also, the ATPRK downscaling could enhance the spatial resolution from 0.25° to 0.05° while preserving the improved accuracy and the spatial pattern of the BMA ensemble, without under- or over-estimation. The quality-improved data sets can contribute to a variety of local and regional applications related to soil moisture, such as agriculture, forest, hydrology, and meteorology. Because the ensemble downscaling method can be applied to the other land surface variables such as temperature, humidity, precipitation, and evapotranspiration, it can be a viable option to complement the accuracy and the spatial resolution of satellite images and numerical models.

Calculation of Soil Moisture and Evapotranspiration of KLDAS applying Ground-Observed Meteorological Data (지상관측 기상자료를 적용한 KLDAS(Korea Land Data Assimilation System)의 토양수분·증발산량 산출)

  • Park, Gwangha;Kye, Changwoo;Lee, Kyungtae;Yu, Wansik;Hwang, Eui-ho;Kang, Dohyuk
    • Korean Journal of Remote Sensing
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    • v.37 no.6_1
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    • pp.1611-1623
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    • 2021
  • Thisstudy demonstratessoil moisture and evapotranspiration performance using Korea Land Data Assimilation System (KLDAS) under Korea Land Information System (KLIS). Spin-up was repeated 8 times in 2018. In addition, low-resolution and high-resolution meteorological data were generated using meteorological data observed by Korea Meteorological Administration (KMA), Rural Development Administration (RDA), Korea Rural Community Corporation (KRC), Korea Hydro & Nuclear Power Co.,Ltd. (KHNP), Korea Water Resources Corporation (K-water), and Ministry of Environment (ME), and applied to KLDAS. And, to confirm the degree of accuracy improvement of Korea Low spatial resolution (hereafter, K-Low; 0.125°) and Korea High spatial resolution (hereafter, K-High; 0.01°), soil moisture and evapotranspiration to which Modern-Era Retrospective analysis for Research and Applications, version 2 (MERRA-2) and ASOS-Spatial (ASOS-S) used in the previous study were applied were evaluated together. As a result, optimization of the initial boundary condition requires 2 time (58 point), 3 time (6 point), and 6 time (3 point) spin-up for soil moisture. In the case of evapotranspiration, 1 time (58 point) and 2 time (58 point) spin-ups are required. In the case of soil moisture to which MERRA-2, ASOS-S, K-Low, and K-High were applied, the mean of R2 were 0.615, 0.601, 0.594, and 0.664, respectively, and in the case of evapotranspiration, the mean of R2 were 0.531, 0.495, 0.656, and 0.677, respectively, indicating the accuracy of K-High was rated as the highest. The accuracy of KLDAS can be improved by securing a large number of ground observation data through the results of this study and generating high-resolution grid-type meteorological data. However, if the meteorological condition at each point is not sufficiently taken into account when converting the point data into a grid, the accuracy is rather lowered. For a further study, it is expected that higher quality data can be produced by generating and applying grid-type meteorological data using the parameter setting of IDW or other interpolation techniques.

Numerical Study on the Impact of the Spatial Resolution of Wind Map in the Korean Peninsula on the Accuracy of Wind Energy Resources Estimation (한반도 풍력 자원 지도의 공간 해상도가 풍력자원 예측 정확도에 미치는 영향에 관한 수치연구)

  • Lee, Soon-Hwan;Lee, Hwa-Woon;Kim, Dong-Hyuk;Kim, Min-Jung;Kim, Hyun-Goo
    • Journal of Environmental Science International
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    • v.18 no.8
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    • pp.885-897
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    • 2009
  • In order to make sure the impact of spatial resolution of wind energy map on the estimation of wind power density in the Korean Peninsula, the comparison studies on the characteristics of wind energy map with three different spatial resolutions were carried out. Numerical model used in the establishment of wind map is MM5 (5th generation Mesoscale Model) with RBAPS (Regional Data Assimilation and Prediction System) as initial and boundary data. Analyzed Period are four months (March, August, October, and December), which are representative of four seasons. Since high spatial resolution of wind map make the undulation of topography be clear, wind pattern in high resolution wind map is correspond well with topography pattern and maximum value of wind speed is also increase. Indication of island and mountains in wind energy map depends on the its spatial resolution, so wind patterns in Heuksan island and Jiri mountains are clearly different in high and low resolutions. And area averaged power density can be changed by estimation method of wind speed for unit area in the numerical model and by treatment of air density. Therefore the studiable resolution for the topography should be evaluated and set before the estimation of wind resources in the Korean Peninsula.

Interactions between Soil Moisture and Weather Prediction in Rainfall-Runoff Application : Korea Land Data Assimilation System(KLDAS) (수리 모형을 이용한 Korea Land Data Assimilation System (KLDAS) 자료의 수문자료에 대한 영향력 분석)

  • Jung, Yong;Choi, Minha
    • 한국방재학회:학술대회논문집
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    • 2011.02a
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    • pp.172-172
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    • 2011
  • The interaction between land surface and atmosphere is essentially affected by hydrometeorological variables including soil moisture. Accurate estimation of soil moisture at spatial and temporal scales is crucial to better understand its roles to the weather systems. The KLDAS(Korea Land Data Assimilation System) is a regional, specifically Korea peninsula land surface information systems. As other prior land data assimilation systems, this can provide initial soil field information which can be used in atmospheric simulations. For this study, as an enabling high-resolution tool, weather research and forecasting(WRF-ARW) model is applied to produce precipitation data using GFS(Global Forecast System) with GFS embedded and KLDAS soil moisture information as initialization data. WRF-ARW generates precipitation data for a specific region using different parameters in physics options. The produced precipitation data will be employed for simulations of Hydrological Models such as HEC(Hydrologic Engineering Center) - HMS(Hydrologic Modeling System) as predefined input data for selected regional water responses. The purpose of this study is to show the impact of a hydrometeorological variable such as soil moisture in KLDAS on hydrological consequences in Korea peninsula. The study region, Chongmi River Basin, is located in the center of Korea Peninsular. This has 60.8Km river length and 17.01% slope. This region mostly consists of farming field however the chosen study area placed in mountainous area. The length of river basin perimeter is 185Km and the average width of river is 9.53 meter with 676 meter highest elevation in this region. We have four different observation locations : Sulsung, Taepyung, Samjook, and Sangkeug observatoriesn, This watershed is selected as a tentative research location and continuously studied for getting hydrological effects from land surface information. Simulations for a real regional storm case(June 17~ June 25, 2006) are executed. WRF-ARW for this case study used WSM6 as a micro physics, Kain-Fritcsch Scheme for cumulus scheme, and YSU scheme for planetary boundary layer. The results of WRF simulations generate excellent precipitation data in terms of peak precipitation and date, and the pattern of daily precipitation for four locations. For Sankeug observatory, WRF overestimated precipitation approximately 100 mm/day on July 17, 2006. Taepyung and Samjook display that WRF produced either with KLDAS or with GFS embedded initial soil moisture data higher precipitation amounts compared to observation. Results and discussions in detail on accuracy of prediction using formerly mentioned manners are going to be presented in 2011 Annual Conference of the Korean Society of Hazard Mitigation.

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Prediction and Analysis of PM2.5 Concentration in Seoul Using Ensemble-based Model (앙상블 기반 모델을 이용한 서울시 PM2.5 농도 예측 및 분석)

  • Ryu, Minji;Son, Sanghun;Kim, Jinsoo
    • Korean Journal of Remote Sensing
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    • v.38 no.6_1
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    • pp.1191-1205
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    • 2022
  • Particulate matter(PM) among air pollutants with complex and widespread causes is classified according to particle size. Among them, PM2.5 is very small in size and can cause diseases in the human respiratory tract or cardiovascular system if inhaled by humans. In order to prepare for these risks, state-centered management and preventable monitoring and forecasting are important. This study tried to predict PM2.5 in Seoul, where high concentrations of fine dust occur frequently, using two ensemble models, random forest (RF) and extreme gradient boosting (XGB) using 15 local data assimilation and prediction system (LDAPS) weather-related factors, aerosol optical depth (AOD) and 4 chemical factors as independent variables. Performance evaluation and factor importance evaluation of the two models used for prediction were performed, and seasonal model analysis was also performed. As a result of prediction accuracy, RF showed high prediction accuracy of R2 = 0.85 and XGB R2 = 0.91, and it was confirmed that XGB was a more suitable model for PM2.5 prediction than RF. As a result of the seasonal model analysis, it can be said that the prediction performance was good compared to the observed values with high concentrations in spring. In this study, PM2.5 of Seoul was predicted using various factors, and an ensemble-based PM2.5 prediction model showing good performance was constructed.

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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