• 제목/요약/키워드: spatial scale

검색결과 1,663건 처리시간 0.026초

Effects of subbasin spatial scale on runoff simulation using SWAT

  • Tegegne, Getachew;Kim, Youngil;Seo, Seung Beom
    • 한국수자원학회:학술대회논문집
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    • 한국수자원학회 2018년도 학술발표회
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    • pp.156-156
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    • 2018
  • The subbasin spatial scale can affect a hydrological simulation result. The objective of this study was to investigate an appropriate subbasin spatial scale for reproducing the different flow phases with the Soil and Water Assessment Tool (SWAT). Moreover, this study addressed the total hydrologic model uncertainty using the Generalized Likelihood Uncertainty Estimation (GLUE) method. The hydrologic modelling uncertainty analysis revealed that the courser subbasin spatial scale provided a relatively better coverage of most of the observations by the 95PPU. On the other hand, the finer subbasin spatial scale produced the best single simulation output closer to the observation. Moreover, most of the observed high flows were enveloped by the 95PPU while this did not happen for the low flows. The overall average performance improvement through an appropriate subbasin spatial scale for reproducing the different flow phases in the Yongdam and Gilgelabay watersheds were found to be 36% and 53%, respectively. It is, therefore, a worth that to put more effort in reproducing the different flow phases by investigating an appropriate subbasin spatial scale to improve our understanding about the frequency and magnitude of the different flow phases.

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Development of an R-based Spatial Downscaling Tool to Predict Fine Scale Information from Coarse Scale Satellite Products

  • Kwak, Geun-Ho;Park, No-Wook;Kyriakidis, Phaedon C.
    • 대한원격탐사학회지
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    • 제34권1호
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    • pp.89-99
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    • 2018
  • Spatial downscaling is often applied to coarse scale satellite products with high temporal resolution for environmental monitoring at a finer scale. An area-to-point regression kriging (ATPRK) algorithm is regarded as effective in that it combines regression modeling and residual correction with area-to-point kriging. However, an open source tool or package for ATPRK has not yet been developed. This paper describes the development and code organization of an R-based spatial downscaling tool, named R4ATPRK, for the implementation of ATPRK. R4ATPRK was developed using the R language and several R packages. A look-up table search and batch processing for computation of ATP kriging weights are employed to improve computational efficiency. An experiment on spatial downscaling of coarse scale land surface temperature products demonstrated that this tool could generate downscaling results in which overall variations in input coarse scale data were preserved and local details were also well captured. If computational efficiency can be further improved, and the tool is extended to include certain advanced procedures, R4ATPRK would be an effective tool for spatial downscaling of coarse scale satellite products.

중간 속도 규모를 이용한 바람장의 균질성 평가 및 영향요소 분석 (The assessment of the Spatial Variation of the Wind Field using the Meso-velocity Scale and its Contributing Factors)

  • 이성은;신선희;하경자
    • 대기
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    • 제20권3호
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    • pp.343-353
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    • 2010
  • A regional wind network with complex surface conditions must be designed with sufficient space and time resolution to resolve the local circulations. In this study, the spatial variations of the wind field observed in the Seoul and Jeju regional networks were evaluated in terms of annual, seasons, and months to assess the spatial homogeneity of wind fields within the regional networks. The coherency of the wind field as a function of separation distance between stations indicated that significant coherency was sometimes not captured by the network, as inferred by low correlations between adjacent stations. A meso-velocity scale was defined in terms of the spatial variability of the wind within the network. This problem is predictably most significant with weak winds, dull prevailing wind, clear skies and significant topography. The relatively small correlations between stations imply that the wind at a given point cannot be estimated by interpolating winds from the nearest stations. For the Seoul and Jeju regional network, the meso-velocity scale has typically a same order of magnitude as the speed of the network averaged wind, revealing the large spatial variability of the Jeju network station imply topography and weather. Significant scatter in the relationship between spatial variability of the wind field and the wind speed is thought to be related to thermally-generated flows. The magnitude of the mesovelocity scale was significantly different along separation distance between stations, wind speed, intensity of prevailing wind, clear and cloudy conditions, topography. Resultant wind vectors indicate much different flow patterns along condition of contributing factors. As a result, the careful considerations on contributing factors such as prevailing wind in season, weather, and complex surface conditions with topography and land/sea contrast are required to assess the spatial variations of wind field on a regional network. The results in the spatial variation from the mesovelocity scale are useful to represent the characteristics of regional wind speed including lower surface conditions over the grid scale of large scale atmospheric model.

소규모 주거공간의 효율적 활용을 위한 공간계획 사례연구 (Case Study of Spatial Planning for the Efficient Use of Small Dwelling Space)

  • 박시윤;김정아
    • 한국주거학회논문집
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    • 제25권1호
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    • pp.15-22
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    • 2014
  • In the domestic housing market, uncompleted lot-solid apartments and unoccupied residences are increasing in the medium-large scale area whose rents and transactions have been unstable, as going through the financial crisis and economical recession. Demands for small-scale housings are steadily increasing by practical consumer group who don't need large places, which are often not needed for the current people who are spending most of their time outside of their houses. Therefore, this study proposes the useful methods for spatial planning for small-scale houses for multiple households, including variable form, levels form, multi-level form, and smart-sizing. For efficient spatial planning for that purpose, here, small-scale housings are not limited to places for families with 1-2 members, but considered as one of broader approaches to graft various households and families. In addition, we examined the existed trends of researches about spatial utility of small-scale places, and did the research about the status of small-scale housing developments, and then proposed the direction for future small-scale housings by analyzing the advanced examples.

Assessing the Impacts of Errors in Coarse Scale Data on the Performance of Spatial Downscaling: An Experiment with Synthetic Satellite Precipitation Products

  • Kim, Yeseul;Park, No-Wook
    • 대한원격탐사학회지
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    • 제33권4호
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    • pp.445-454
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    • 2017
  • The performance of spatial downscaling models depends on the quality of input coarse scale products. Thus, the impact of intrinsic errors contained in coarse scale satellite products on predictive performance should be properly assessed in parallel with the development of advanced downscaling models. Such an assessment is the main objective of this paper. Based on a synthetic satellite precipitation product at a coarse scale generated from rain gauge data, two synthetic precipitation products with different amounts of error were generated and used as inputs for spatial downscaling. Geographically weighted regression, which typically has very high explanatory power, was selected as the trend component estimation model, and area-to-point kriging was applied for residual correction in the spatial downscaling experiment. When errors in the coarse scale product were greater, the trend component estimates were much more susceptible to errors. But residual correction could reduce the impact of the erroneous trend component estimates, which improved the predictive performance. However, residual correction could not improve predictive performance significantly when substantial errors were contained in the input coarse scale data. Therefore, the development of advanced spatial downscaling models should be focused on correction of intrinsic errors in the coarse scale satellite product if a priori error information could be available, rather than on the application of advanced regression models with high explanatory power.

소규모 미술관에 나타나는 현상학적 요소에 관한 연구 - 메를로 퐁티의 지각의 현상학을 중심으로 - (A Study on the Phenomenological Elements Appearing in Small-Scale Art Museums - From the Viewpoint of Phenomenology of Perception of M. Merleau-Ponty -)

  • 최진석;김문덕
    • 한국실내디자인학회논문집
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    • 제23권3호
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    • pp.212-221
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    • 2014
  • This study aims to analyze and explore phenomenological elements that appear in small-scall art museums with spatial concepts, such as top and bottom, depth, movement, and experienced space on the basis of Merleau-Ponty $Ph\acute{e}nom\acute{e}nologie$ de la perception.' Therefore, small-scale art museums may be regarded as an ideal space that can be analyzed with Merleau-Ponty's phenomenological theory since they should provide viewers with various spatial experiences in a limited space, breaking away from spatial limitations beyond appreciation of artworks. As research subjects, the range of art museums was limited to ones whose designs architectures or interior designers participated in out of all the small-scale art museums constructed after the 1990s, when the concepts and directing methods of spatial experience elements started being applied to art museums. Small-scale art museums chosen as cases were analyzed with Merleau-Ponty's spatial concepts explained earlier, and this study drew conclusions for each one. The significance of this study is that the results of this study can be used as efficient materials to reflect phenomenological elements on planning future small-scale art museums through further studies on various small-scale art museums.

대학 캠퍼스 공간적 지표에 의한 유형화에 관한 연구 (A Study on the Classification by the Spatial Index of the University Campuses)

  • 김천일;신소영;김익환
    • 교육시설 논문지
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    • 제23권4호
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    • pp.3-10
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    • 2016
  • This paper presents the investigation results on the classification of the university campuses. For the classification, we selected the spatial index as the evaluation indicator since the environmental factors and maintenance methods vary from university campus to university campus. For the study, we used eight spatial indices of the 30 national universities. This paper provides the spatial characteristics of different campus types, presents campus classification analysis as a future research approach to campus maintenance, and provides the data for the future study of comparison among universities. The results are as follows. 1) The classification investigation categorized the university campuses into three groups. Type 1 is a large-scale type, located near downtown. Type 2 is a medium-scale type, located at a remote site from downtown. Type 3 is a small-scale type, which is located comparatively near downtown. 2) Type 1 is a large-scale mixed area type, and 13 universities belong to this group. Type 2 is a medium-scale suburban area type, and six universities are in this group. Finally, Type 3 is a small-scale downtown area type, and 11 universities belong to this group.

MRSPAKE : Hadoop MapReduce를 이용한 웹 규모의 공간 지식 추출기 (MRSPAKE : A Web-Scale Spatial Knowledge Extractor Using Hadoop MapReduce)

  • 이석준;김인철
    • 정보처리학회논문지:소프트웨어 및 데이터공학
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    • 제5권11호
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    • pp.569-584
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    • 2016
  • 본 논문에서는 Hadoop MapReduce 병렬 분산 컴퓨팅 환경을 이용해 개발한 공간 지식 추출기를 제안한다. 이 공간 지식 추출기는 대용량의 공간 데이터 집합으로부터, 임의의 두 공간 객체들 사이에 만족되는 위상 관계와 방향 관계를 나타내는 정성 공간 지식 베이스를 생성해낸다. 본 논문에서 제안하는 MapReduce 기반의 대용량 공간 지식 추출기 MRSPAKE는 HDFS 상의 분산 공간 데이터 파일에 대한 R 트리 색인과 범위 질의들을 이용함으로써, 웹 규모의 정성 공간 지식 베이스를 매우 효율적으로 추출해낸다. 대표적인 공개 데이터 집합인 Open Street Map(OSM)을 이용한 성능 분석 실험을 통해, 본 논문에서 제안하는 웹 규모의 공간 지식 추출기 MRSPAKE의 높은 성능과 확장성을 확인할 수 있었다.

해상도 변화에 따른 공간 데이터의 구조특성 분석 (Analysis of Spatial Structure in Geographic Data with Changing Spatial Resolution)

  • 구자용
    • Spatial Information Research
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    • 제8권2호
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    • pp.243-255
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    • 2000
  • 공간상에 분포한 각종 지리사상들은 다양한 분석기법을 통하여 분포특성과 패턴이 파악된다. 이때 축척(scale)은 공간분석 기법에서 연구자가 고려해야 할 중요한 요인중의 하나이다. 이 연구에서는 해상도 저감에 따라 변화하는 공간 데이터의 구조특성을 표현할 수 있는 기법을 비교 분석하여 공간분석에 필요한 적정해상도의 모색과정에 이용하고자 한다. 순천만 해안습지의 LANSAT TM 데이터를 대상으로 하여, 데이터의 구조특성이 해상도에 따라 변화하는 특성을 살펴보고 이를 반영할 수 있는 해상도 특성 지수들을 비교평가 하였다. 기존에 개발된 국지적 분산(local variance)과 프랙탈차원을 적용하였고, 해상도 변화과정에서 파생되는 분산 데이터의 공간분포 패턴을 표현하는 지수로 공간적 자기관도인 Moran´s I를 측정하였다. 구조특성 분석기법을 적용한 결과 기존에 개발된 국지적 분산과 프랙탈 차원보다는 분산 데이터의 공간적 자기상관도가 구조특성을 분석하는 기법으로 적합하게 나타났다. 공간적 자기상관도가 정점인 해상도에서 공간 데이터의 변화가 심하게 나타나고 있다. 공간 데이터의 구조특성은 탐색하는 기법으로 분산 데이터의 공간적 자기상관도가 효과적인 지수로 작용할 수 있다.

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시스템 사고를 통한 생태계서비스의 trade-off 관계 고찰 (An Analysis of Ecosystem Service's trade-off through Systems Thinking)

  • 함은경;김민;전진형
    • 한국시스템다이내믹스연구
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    • 제16권2호
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    • pp.75-100
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    • 2015
  • The purpose of this study is to analyze causation of Ecosystem service's trade-off(ES trade-off) and to establish baseline data for wise spatial planning and management. In order to understand why and how ES trade-off occurs, systems thinking and causal loops were employed. The causal loop of ecosystem service creation cycle includes profits quantification process, decision making process, spatial planning and management process, and ecosystem services creation process. The profits quantification process has a limitation that all ecosystem service categories were not included in profits quantification, because quantification method for cultural services is insufficient. These problems led to unequal discussion opportunity in decision making process. ES trade-off occurs through transition of ecosystem function in spatial scale and temporal scale. In spatial scale, land-use variation and resource-use variation contribute to change an ecosystem function for different ES category by spatial planning and management. In temporal scale, a change of an ecosystem function for different ES category is influenced by ecological succession, seasonal change and land cover variation, which are parameter from environmental features. This study presented that spatial planning and management should ecosystem service assessment in order to enhance balanced ecosystem services.