• Title/Summary/Keyword: Spatial distribution

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Monitoring of Urban Thermal Environment Change in Daejun Using Landsat TIR Satellite Data (Landsat 열적외 영상자료를 활용한 대전시 열 환경 변화 모니터링)

  • Choi, Jin-Ho;Cho, Hyun-Ju;Jong, Hoan-Do
    • Journal of Environmental Impact Assessment
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    • v.22 no.5
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    • pp.513-523
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    • 2013
  • This purpose of this work is to explore the characteristics of urban thermal environment distribution with the case of Daejeon. To do that, this work applied GIS Spatial Statistics to the LandSAT images gathered from 2000 to 2011. The urban thermal environment distribution at the time point of 2 showed high spatial autocorrelation. Therefore, it is judged that spatial autocorrelation is needed to increase the reliability and explanatory power of the characteristics of thermal environment distribution. In the case of the thermal in Daejeon, its positive clustering appeared high at the time point of 2, and its clustering in 2011 more gradually decreased than that in 2000 to 2011. In particular, given the decrease in the core H-H region, it was found that the thermal environment of Daejeon was greatly improved. However, since the rise in the region L-L means another changed like construction of a new city, it is judged that it is necessary to come up with a proper plan. It is considered that this analysis of the characteristics of urban thermal environment distribution in consideration of spatial autocorrelation L-L be useful for providing a fundamental material necessary for the policy and project of thermal environment improvement.

Comparison of Spatial Distributions of Rainfall Derived from Rain Gages and a Radar (우량계와 강우레이다에 의해 관측된 강우량의 공간 분포 비교)

  • Kim, Byung-Sik;Kim, Hung-Soo;Yang, Dong-Min
    • Journal of Wetlands Research
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    • v.12 no.1
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    • pp.63-73
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    • 2010
  • Rainfall is one of the most important input data of hydrologic models. Rain gage is used to estimate areal rainfall for hydrologic models using several interpolation method such as Thiessen polygon, Inverse Distance Squared(IDS) and Kriging. However, it is still difficult to derive actual spatial distribution of the rainfall using the aforementioned approaches. On the other hand, radar can offer a significant analytic improvement for rainfall analysis by providing directly more representative of the true spatial distribution of rainfall. In this study, In this study, spatial distributions of rainfall derived form rain gages using IDS and Kriging and rainfall from radar are compared. As results, it is found that using radar can provide actual spatial distribution than rain gages.

Estimation of spatial distribution of precipitation by using of dual polarization weather radar data

  • Oliaye, Alireza;Bae, Deg-Hyo
    • Proceedings of the Korea Water Resources Association Conference
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    • 2021.06a
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    • pp.132-132
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    • 2021
  • Access to accurate spatial precipitation in many hydrological studies is necessary. Existence of many mountains with diverse topography in South Korea causes different spatial distribution of precipitation. Rain gauge stations show accurate precipitation information in points, but due to the limited use of rain gauge stations and the difficulty of accessing them, there is not enough accurate information in the whole area. Weather radars can provide an integrated precipitation information spatially. Despite this, weather radar data have some errors that can not provide accurate data, especially in heavy rainfall. In this study, some location-based variable like aspect, elevation, plan curvature, profile curvature, slope and distance from the sea which has most effect on rainfall was considered. Then Automatic Weather Station data was used for spatial training of variables in each event. According to this, K-fold cross-validation method was combined with Adaptive Neuro-Fuzzy Inference System. Based on this, 80% of Automatic Weather Station data was used for training and validation of model and 20% was used for testing and evaluation of model. Finally, spatial distribution of precipitation for 1×1 km resolution in Gwangdeoksan radar station was estimates. The results showed a significant decrease in RMSE and an increase in correlation with the observed amount of precipitation.

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Spatial distribution patterns of old-growth forest of dioecious tree Torreya nucifera in rocky Gotjawal terrain of Jeju Island, South Korea

  • Shin, Sookyung;Lee, Sang Gil;Kang, Hyesoon
    • Journal of Ecology and Environment
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    • v.41 no.8
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    • pp.223-234
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    • 2017
  • Background: Spatial structure of plants in a population reflects complex interactions of ecological and evolutionary processes. For dioecious plants, differences in reproduction cost between sexes and sizes might affect their spatial distribution. Abiotic heterogeneity may also affect adaptation activities, and result in a unique spatial structure of the population. Thus, we examined sex- and size-related spatial distributions of old-growth forest of dioecious tree Torreya nucifera in extremely heterogeneous Gotjawal terrain of Jeju Island, South Korea. Methods: We generated a database of location, sex, and size (DBH) of T. nucifera trees for each quadrat ($160{\times}300m$) in each of the three sites previously defined (quadrat A, B, C in Site I, II, and III, respectively). T. nucifera trees were categorized into eight groups based on sex (males vs. females), size (small vs. large trees), and sex by size (small vs. large males, and small vs. large females) for spatial point pattern analysis. Univariate and bivariate spatial analyses were conducted. Results: Univariate spatial analysis showed that spatial patterns of T. nucifera trees differed among the three quadrats. In quadrat A, individual trees showed random distribution at all scales regardless of sex and size groups. When assessing univariate patterns for sex by size groups in quadrat B, small males and small females were distributed randomly at all scales whereas large males and large females were clumped. All groups in quadrat C were clustered at short distances but the pattern changed as distance was increased. Bivariate spatial analyses testing the association between sex and size groups showed that spatial segregation occurred only in quadrat C. Males and females were spatially independent at all scales. However, after controlling for size, males and females were spatially separated. Conclusions: Diverse spatial patterns of T. nucifera trees across the three sites within the Torreya Forest imply that adaptive explanations are not sufficient for understanding spatial structure in this old-growth forest. If so, the role of Gotjawal terrain in terms of creating extremely diverse microhabitats and subsequently stochastic processes of survival and mortality of trees, both of which ultimately determine spatial patterns, needs to be further examined.

Analysis of Spatial Population Distribution and Network Accessibility in Urban Areas (도시인구의 공간적분포와 접근도분석)

  • 김형철
    • Journal of Korean Society of Transportation
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    • v.7 no.1
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    • pp.57-70
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    • 1989
  • The purpose of study is to analyze the spatial population distribution and accessibility of network in urban areas. This study examines the forty-six political subdivision cities in Korea at the end of 1983, except the four metrpolitans (Seoul, Pusan, Daeku and Incheon). Evaluation indexes are classified the spatial pupulation distribution and accessibility of network. To analyze the cities, 10 indexes and the statistical techniques such as descriptive analysis, correlation analysis, factor analysis and cluster analysis were used. According to the results of cluster analysis, 15 cities (Ulsasn, Suwon, Bucheon, Chungju and etc.) are classified dispersed cities and another 15 cities (Kwangju, Daejun, Sungnam, Mokpo and etc.) are classified concentrated cities.

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Spatial Distribution of Injected Charge Carriers in SONOS Memory Cells

  • Kim Byung-Cheul;Seob Sun-Ae
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2006.05a
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    • pp.894-897
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    • 2006
  • Spatial distribution of injected electrons and holes is evaluated by using single-junction charge pumping technique in SONOS(Poly-silicon/Oxide/Nitride/Oxide/Silicon) memory cells. Injected electron are limited to length of ONO(Oxide/Nitride/oxide) region in locally ONO stacked cell, while are spread widely along with channel in fully ONO stacked cell. Hot-holes are trapped into the oxide as well as the ONO stack in locally ONO stacked cell.

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A Review of Ecological and Natural Map Grades and Public Appeals in Korea

  • Wooseok Oh;Jangsam Cho;Kihyun Park;Hyosun Leem;Eui-Jeong Ko;Changhoon You;Jeong-Cheol Kim;Hye-Yeon Yoon
    • Proceedings of the National Institute of Ecology of the Republic of Korea
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    • v.4 no.4
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    • pp.141-145
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    • 2023
  • This study surveyed the changes in the proportion of Ecological and Natural Map (ENM) grades in Korea, the distribution ratio of ENM 1st-grade areas by region, and the current status of regional public appeals for the five-year period from 2017 to 2021. The nationwide changes in ENM grades revealed an increase in 1st-grade, 3rd-grade, and separately managed areas but a decrease in the ratio of 2nd-grade areas. Nationwide, Gangwon had the highest distribution ratio of 1st-grade areas, at 46.77%, while Gwangju had the lowest, at 0.05%. In the five-year study period, 383 appeals concerning ENM grades were received and processed. Gangwon had the greatest number of appeals, with 96, while Sejong had the fewest, with 1. A significant correlation was observed between the distribution ratio of 1st-grade areas and public appeals.

Spatial Distribution Pattern of Users by the Types of Use Activity at Lawn Areas in Park (공원잔디공간의 이용활동유형별 공간분포특성에 관한 연구)

  • 암봉훈
    • Asian Journal of Turfgrass Science
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    • v.10 no.1
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    • pp.13-20
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    • 1996
  • This study was carried out to investigate the characteristics of spatial distributon patterns of users by each type of recreational activities at lawn areas in the parks. Study sites were lawn areas at Kyungju World and Seorabul Plaza in Bomun Resort Complex in Kyungju, Korea. Space types by each recreation activities are Repose Type, Sports Type, Play Type and Strolling Type. Main results are as follows ; 1. Sport Type activities were mainly distributed at the central areas of each lawn areas. 2.The density of Sports Type activities were affected by the form of lawn areas. For natural control of excess dynamic activities, Complex Form has more advantage in the distribution of dynamic activities. So, as the form of lawn areas in the parks, complex form is more desirable. 3.Repose Typo activities were distributed at marginal areas of lawns and surrounding woods. These, the static activities, were affected by Edge Effect in spatial distribution of activities. 4.Play Typo activities also were distributed at marginal areas of lawns. It was also affected by Edge Effect in spatial distribution. 5.Strolling Type activities were distributed evenly over all lawn areas.

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Measurement of the Spatial Dose Rate for Distribution Room in Department of Nuclear Medicine (핵의학과 분배실 내의 공간선량률 측정)

  • Park, Jeong-Kyu;Cho, Euy-Hyun
    • Journal of Digital Contents Society
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    • v.13 no.2
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    • pp.151-157
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    • 2012
  • Even though the protective facility is well made with the development of medicine, the spatial dose within the radiation section could increase the exposure of the workers. The spatial dose is always present in distribution room within the Department of Nuclear Medicine, so the spatial dose of the interior distribution room is measured and analyzed for the prediction of the exposure dose. The spatial dose rate was $6.78{\pm}0.083{\mu}Sv/h$ in the $^{18}F$ distribution room of department of Nuclear Medicine, $9.248{\pm}0.013{\mu}Sv/h$ in $^{99m}Tc$, and $^{131}I$ distribution room. In addition, in case of $^{18}F$ distribution room, the yearly external exposure dose was $42.5{\mu}Sv$ when the nurse does IV in 1m in distance. It also showed that the spatial dose rate on the direction of right oblique showed higher than others by the standard of distribution window of distribution room. Therefore, the staying time of the workers should be short during distributing radiopharmaceuticals in the distribution room and the design of the distribution protection is necessary to reduce the exposure in the direction of right oblique of the protection. The utmost endeavors are required to reduce the worker's individual exposure dose while doing IV.

On the spatial distribution of satellite galaxies around Milky-way-like galaxies in cosmological simulations

  • Kim, Seoneui;Yoon, Suk-Jin
    • The Bulletin of The Korean Astronomical Society
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    • v.42 no.2
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    • pp.72.3-73
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    • 2017
  • The spatial distribution of sub-halos in a large host halo is usually described as isotropic in the ${\Lambda}CDM$ cosmology. Recent observations, however, show that satellite galaxies around massive galaxies are often located within a preferred plane. In order to understand the origin of such planar alignment, we investigate the spatial distribution of sub-halos around their hosts by using the hydrodynamic cosmological simulation, Illustris. In particular, we analyze the systems resembling the Milky Way (MW) and its satellites, i.e. consisting of MW-sized central galaxy and its at least 11 satellites. The result shows that ~10 % of MW-like systems have the anisotropic satellite galaxy distribution at z = 0. The satellites that are accreted more recently tend to form a flattened structure more frequently, indicating a link of satellite distribution to the surrounding environment. We discuss the physical origin of the anisotropic satellite distribution from the viewpoint of the ${\Lambda}CDM$ paradigm.

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