• Title/Summary/Keyword: spatial aggregation

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Influence of Scaling in Drone-based Remotely Sensed Information on Actual Evapotranspiration Estimation (드론 원격정보 격자크기가 실제증발산량 산정에 미치는 영향)

  • Lee, Khil-Ha
    • Journal of Environmental Science International
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    • v.27 no.2
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    • pp.135-141
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    • 2018
  • The specification of surface vegetation is essential for simulating actual evapotranspiration of water resources. The availability of land cover maps based on remotely collected data makes the specification of surface vegetation easier. The spatial resolution of hydrologic models rarely matches the spatial scales of the vegetation data needed, and remotely collected vegetation data often are upscaled up to conform to the hydrologic model scale. In this study, the effects of the grid scale of of surface vegetation on the results of actual evapotranspiration were examined. The results show that the coarser resolution causes larger error in relative terms and that a more realistic description of area-averaged vegetation nature and characteristics needs to be considered when calculating actual evapotranspiration.

Estimating the Spatial Distribution of Satellite Image Classification Error Using Index of Spatial Distribution (공간분포지표를 이용한 위성영상 분류오차의 공간적 분포 평가)

  • 이병길;김용일;어양담
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.17 no.2
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    • pp.129-136
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    • 1999
  • The quality of image classification results is not always uniform over entire image. Thus, this study proposes the concept of ISDd (Index of Spatial Distribution by distance) and ISDs (ISD by scatteredness) for the evaluation of unevenness of result quality, and spatial distribution of satellite image classification errors. The ISDd is indexed mean distance of misclassified pixels and the ISDs is statistical indicator of scatteredness of misclassified pixels. In this study, the ISDd and the ISDs are calculated and evaluated for some satellite images, then misclassified area is extracted and the reasons of misclassification are examined. As the result of this study, using both the ISDd and the ISDs, the basis of decision on adoption/rejection of classification results is offered at sub-image level by evaluation of the local aggregation of misclassified pixels. Using Index of Spatial Distribution. as well as overall classification accuracy, users can understand the spatial distribution of misclassified pixels, and can have the additional criterion of the judgement on suitability and reliability of classification results.

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Change in Spatial Dispersion of Daphnia magna(Cladocera: Daphniidae) Populations Exposed to Organophosphorus Insecticide, Diazinon (유기인계 살충제 (다이아지논)에 대한 물벼룩, Daphnia magna (Cladocera: Daphniidae) 개체군의 공간분산 변이)

  • Lee, Sang-Hee;Ji, Chang-Woo;Chon, Tae-Soo
    • Environmental Analysis Health and Toxicology
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    • v.24 no.3
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    • pp.231-240
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    • 2009
  • We explored collective behaviors of indicator species to elucidate the effect of the chemical stress. After the treatments of an insecticide, diazinon, at low concentrations (1.0 and 10.0 ${\mu}g/L$), spatial dispersion patterns of Daphnia magna were checked in a test chamber. The I-index was used to characterize the movement data before (0~1 h) and after (1~2 h) the treatments in laboratory conditions. The slopes of the frequency distribution of I-index in semi-log scale decreased significantly, and the test populations appeared to be more dispersed with a lower degree of aggregation after the treatments. The index was feasible in indicating decrease in the ability of the specimens to keep desirable distances with neighbor individuals under chemical stress and showed a possibility of monitoring presence of toxic chemicals in environment through group behavior measurement.

Spatial Characteristic Analysis for the Main Production Areas of Vegetables based on Landscape Indices (경관지수를 활용한 채소 주산지 공간적 분포 특성 분석)

  • Bae, Seung-jong;Kim, Dae-Sik;Kim, Soo-Jin;Oh, Yun-Gyeong
    • Journal of Korean Society of Rural Planning
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    • v.23 no.1
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    • pp.135-146
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    • 2017
  • The objective of this study is to accurately understand the spatial distribution characteristics of the main production area for the three vegetable crops such as Chinese cabbage, radish, and hot pepper. We applied the 8 landscape indices such as TA, NP, PD, LPI, LSI, PLADJ, COHESION, and CONNECT to 35 cities and counties using FRAGSTATS. In the case of main production area for Chinese cabbage, six cities and counties in Gangwon province were revealed as a relatively high degree of aggregation by cultivation parcels than other area. In addition, Gangneung city and Hongcheon county have been analyzed to be the most aggregated area in the case of radish and hot pepper, respectively. In the future, the spatial analysis method used in this study would be helpful to develop an effective regional plan of the main production area.

SPATIAL DISTRIBUTION OF FAECES BY CATTLE IN A DAYTIME GRAZING SYSTEM

  • Hirata, M.;Higashiyama, M.
    • Asian-Australasian Journal of Animal Sciences
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    • v.9 no.5
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    • pp.603-610
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    • 1996
  • Spatial distribution of faeces by Japanese Black heifers and steers was investigated. The animals grazed a bahiagrass (Paspalum notatum $Fl\ddot{u}gge$) pasture in the daytime from 9 a.m. to 4 p.m., and spent the rest of the day in a barn. The pasture consisted of three paddocks, an alley and a resting area, and the paddocks were grazed rotationally. The number of defecations and the faecal weight excreted in the pasture were greater than those expected from the proportion of time that the animals spent in the pasture. These values were correspondingly smaller in the barn. The distribution of faeces to the paddock, alley and resting area of the pasture was usually not proportional to the area of the respective places. The number of defeations and the faecal weight were usually distributed less densely in the paddock than in the resting area. The degree of aggregation of defecation in the paddock, alley and resting area varied with the meteorological factors such as the air temperature, solar radiation and rainfall during the grazing, and the intake of hay supplement of the previous day.

Spatial Distribution of Urination by Cattle in a Daytime Grazing System

  • Hirata, M.;Higashiyama, M.
    • Asian-Australasian Journal of Animal Sciences
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    • v.10 no.5
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    • pp.484-490
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    • 1997
  • Spatial distribution of urination by Japanese Black heifers and steers was investigated, and compared with the distribution of defecation. The animals grazed a bahiagrass (Paspalum notatum $Fl\ddot{u}gge$) pasture in the daytime, and spent the rest of the day in a barn. The distribution of urination to the pasture was greater than that expected from the proportion of time that the animals spent in the pasture. Correspondingly, the distribution was smaller in the barn. Such a distribution pattern of urination to the pasture and barn was similar to that of defecation, and affected by the intake of supplement on the previous day. The distribution of urination within the pasture, i.e. the distribution to the paddock, alley and resting area, was often uneven on an area basis. The animals often urinated sparsely in the alley and resting area, while they urinated in the paddock almost proportionally to its area. This was a clear contrast to the distribution pattern of defecation, which was sparse in the paddock and dense in the resting area. The degree of aggregation of urination in the paddock, alley and resting area varied with the meteorological factors and the intake of supplement.

A Study on Manufacturing Aggregation And Carbon Emission Intensity: Application of Spatial Panel Regression (국내 제조업 집적이 탄소 배출 강도에 미치는 영향: 공간패널회귀모형의 적용)

  • Zhen Wu;Hyun-Chung Kim
    • Korea Trade Review
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    • v.47 no.3
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    • pp.157-175
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    • 2022
  • This study calculates agglomeration indices of manufacturing specialization and diversification in different regions of South Korea. Two types of agglomeration indices are introduced into the spatial durbin model (SDM) to analyzes the effects of manufacturing agglomeration in Korea on CO2 emission intensity. The subjects of this study are 17 regions of South Korea , and the research period is from 2013 to 2019. This study also uses partial differential to analyze the direct and spillover effect of specialization and diversification agglomeration on CO2 emission intensity. From the perspective of direct effect, the results reveal that specialization agglomeration is an important factor contributing to Korea's CO2 emissions. However, diversification agglomeration has an obvious CO2 emission reduction effect. From the perspective of spillover effect, this study finds that specialization agglomeration in one region can also contribute to CO2 emissions in nearby regions. However, the development of diversification agglomeration in one region can have CO2 emission reduction spillover effect on neighboring regions.

IMPLEMENTATION OF GIS BASED WATER QUALITY INDICES FOR WATER QUALITY MANAGEMENT

  • Song, Ta-O;Kim, Kye-Hyun
    • Proceedings of the KSRS Conference
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    • 2007.10a
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    • pp.612-615
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    • 2007
  • Water quality modelling is an ideal tool of simulating physical, chemical and biological changes occurring in water systems. It has been utilized in a number of GIS-based water quality management and analysis applications. However, there is a need of a decision making process to translate the modelling result into an understandable form thereby implement the modelling results to the real world. This paper outlines a new water quality index called the QUAL2E's water quality index (QWQI) based on the water quality modelling using QUAL2E. The development mainly includes four steps: variable selection, sub-index development, weight assignment and sub-index aggregation. An experiment of applying the index and GIS to the Sapgyo River in Korea was implemented. Different from other water quality indices for general water uses, the index is specifically used for the simulated water quality indicators. The index can provide a simple and easy-to-understand decision support. Furthermore, interfacing with GIS, the decision analysis can be performed within a spatial environment. However, more study needs to be made in the future including the improvement of aggregation function.

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Study on Algorithms of Mobile Vector Map Generalization Operators for Location Information Search (위치 정보 검색을 위한 모바일 벡터 지도 일반화 연산 알고리즘 연구)

  • Kim, Hyun-Woo;Choi, Jin-Oh
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • v.9 no.1
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    • pp.167-170
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    • 2005
  • In the mobile environments for the vector map services, a map simplification work through the map generalization steps helps improve the readability of the map on a large scale. The generalization operations are various such as selection, aggregation, simplification, displacement, and so on, the formal operation algorithms have not been built yet. Because the algorithms require deep special knowledge and heuristic, which make it hard to automate the processes. This thesis proposes some map generalization algorithms specialized in mobile vector map services, based on previous works. We will show the detail to adapt the approaches on the mobile environment, to display complex spatial objects efficiently on the mobile devices which have restriction on the resources

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Object Detection and 3D Position Estimation based on Stereo Vision (스테레오 영상 기반의 객체 탐지 및 객체의 3차원 위치 추정)

  • Son, Haengseon;Lee, Seonyoung;Min, Kyoungwon;Seo, Seongjin
    • The Journal of Korea Institute of Information, Electronics, and Communication Technology
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    • v.10 no.4
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    • pp.318-324
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    • 2017
  • We introduced a stereo camera on the aircraft to detect flight objects and to estimate the 3D position of them. The Saliency map algorithm based on PCT was proposed to detect a small object between clouds, and then we processed a stereo matching algorithm to find out the disparity between the left and right camera. In order to extract accurate disparity, cost aggregation region was used as a variable region to adapt to detection object. In this paper, we use the detection result as the cost aggregation region. In order to extract more precise disparity, sub-pixel interpolation is used to extract float type-disparity at sub-pixel level. We also proposed a method to estimate the spatial position of an object by using camera parameters. It is expected that it can be applied to image - based object detection and collision avoidance system of autonomous aircraft in the future.