• Title/Summary/Keyword: spatial distribution patterns

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Pattern Formations with Turing and Hopf Oscillating Pattern in a Discrete Reaction-Diffusion System

  • Lee, Il Hui;Jo, Ung In
    • Bulletin of the Korean Chemical Society
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    • v.21 no.12
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    • pp.1213-1216
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    • 2000
  • Localized structures with fronts connecting a Turing patterns and Hopf oscillations are found in discrete reaction-diffusion system. The Chorite-Iodide-Malonic Acid (CIMA) reaction model is used for a reaction scheme. Localized structures in discrete reaction-diffusion system have more diverse and interesting features than ones in continuous system. Various localized structures can be obtained when a single perturbation is applied with variation of coupling strength of two intermediates. Roles of perturbations are not so simple that perturbations are sources of both Turing patterns and Hopf oscillating domains, and spatial distribution of them is determined by strength of a perturbation applied initially.

Intra-Urban Growth and Spatial Patterns in variation of Poupulation Density-The case of Seoul- (인구밀도의 변화로 본 도시내부의 성장과 공간패턴 - 서울의 예)

  • 이진환
    • Journal of the Korean Geographical Society
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    • v.38
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    • pp.61-74
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    • 1988
  • Changing patterns of population densities in urban centers are different between Western countries and non-Western countries. Although Seoul is located in a non-Western country, the result of this study shows that its pattern of population density falls into the category of Western cities. Through the examination of three population density gradient models, it is clear that no model can precisely explain the population distribution of Seoul over time. Some of the models partly indicate the actual population distrisbution. The Clark model is appropriate to denote population distribution in the center of Seoul at an early stage in development. The Sherratt model cannot adequately explain the population distribution of Seoul.

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Measurements of Local Coercivity Distribution in Ferromagnetic Films Using Magneto-Optical Microscope Magnetometer (MOMM)

  • Choe, Sug-Bong;Shin, Sung-Chul
    • Journal of Magnetics
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    • v.5 no.3
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    • pp.81-84
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    • 2000
  • A magneto-optical microscope magnetometer (MOMM) has been developed to simultaneously measure 2-dimensional array hysteresis loops of each local area of $320\times320-nm^2$ spots on ferromagnetic films, in addition to grabbing time-resolved domain evolution patterns. Using the system, spatial distribution of local coercivity can be quantitatively generated and then, compared directly with domain patterns grabbed at precisely the same position of a sample. It is clearly demonstrated that local coercivity distribution governs domain reversal behavior via a thermally activated relaxation process.

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Spatial Crime Analysis using GIS (GIS를 이용한 범죄의 공간적 특성)

  • Jeon, Jae-Han;Yang, Hyo-Jin;Kwon, Jay-Hyoun
    • Journal of Korean Society for Geospatial Information Science
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    • v.15 no.1 s.39
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    • pp.3-7
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    • 2007
  • To deal with the modern intellectual criminal acts, various efforts have been tried. Especially, it is not difficult to watch the recent activities to analyze the criminal characteristics spatially using computing and GIS technology. In this study, the spatial features and patterns of crime are investigated. Based on the real criminal record in Seoul Korea, the crime is reconstituted with four major categories such as assault, larceny, robbery, and rape. Then the variables are derived based on the theory of criminology. The kernal density analysis is performed to investigate the criminal distribution, and the correlation between the main criminal causes and the criminal outbreak is examined by buffering analysis. In addition, the land price and land usages are correlated with social-economic factors of criminal patterns to produce the final crime map.

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A Study on Spatial Differences in PM2.5 Concentrations According to Synoptic Meteorological Distribution (종관 기상 분포에 따른 PM2.5 농도의 공간적 차이에 관한 연구)

  • Da Eun Chae;Soon-Hwan Lee
    • Journal of Environmental Science International
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    • v.31 no.12
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    • pp.999-1012
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    • 2022
  • To investigate the reason for the spatial difference in PM2.5 (Particulate Matter, < 2.5 ㎛) concentration despite a similar synoptic pattern, a synoptic analysis was performed. The data used for this study were the daily average PM2.5 concentration and meteorological data observed from 2016 to 2020 in Busan and Seoul metropolitan areas. Synoptic pressure patterns associated with high PM2.5 concentration episodes (greater than 35 ㎍/m3) were analyzed using K-means cluster analysis, based on the 900 hPa geopotential height of NCEP (National Centers for Environmental Prediction) FNL (Final analysis) data. The analysis identified three sub-groups related to high concentrations occurring only in Busan and Seoul metropolitan areas. Although the synoptic patterns of high PM2.5 concentration episodes that occur independently in Busan and Seoul metropolitan areas were similar, there was a difference in the intensity of pressure gradient and its direction, which tends to be an important factor determining the movement time of pollutants. The spatial difference in PM2.5 concentration in the Korean Peninsula is due to the difference and direction of the atmospheric pressure gradient that develops from southwest to northeast direction.

Potential Impact of Climate Change on Distribution of Warm Temperate Evergreen Broad-leaved Trees in the Korean Peninsula (기후변화에 따른 한반도 난대성 상록활엽수 잠재서식지 분포 변화)

  • Park, Seon Uk;Koo, Kyung Ah;Kong, Woo-Seok
    • Journal of the Korean Geographical Society
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    • v.51 no.2
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    • pp.201-217
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    • 2016
  • We accessed the climate change effects on the distributions of warm-evergreen broad-leaved trees (shorten to warm-evergreens below) in the Korean Peninsula (KP). For this, we first selected nine warm-evergreens with the northern distribution limits at mid-coastal areas of KP and climate variables, coldest month mean temperature and coldest quarter precipitation, known to be important for warm-evergreens growth and survival. Next, species distribution models (SDMs) were constructed with generalized additive model (GAM) algorithm for each warm-evergreen. SDMs projected the potential geographical distributions of warm evergreens under current and future climate conditions in associations with land uses. The nine species were categorized into three groups (mid-coastal, southwest-coastal, and southeast-inland) based on their current spatial patterns. The effects of climate change and land uses on the distributions depend on the current spatial patterns. As considering land uses, the potential current habitats of all warm-evergreens decrease over 60%, showing the highest reduction rate for the Kyungsang-inland group. SDMs forecasted the expansion of potential habitats for all warm-evergreens under climate changes projected for 2050 and 2070. However, the expansion patterns were different among three groups. The spatial patterns of projected coldest quarter precipitation in 2050 and 2070 could account for such differences.

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Time and Spatial Distribution of Probabilistic Typhoon Storms and Winds in Korean Peninsula (한반도에 내습한 태풍의 확률강우 및 풍속의 시공적 분포 특성)

  • 윤경덕;서승덕
    • Magazine of the Korean Society of Agricultural Engineers
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    • v.36 no.3
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    • pp.122-134
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    • 1994
  • The objective of this study is to provide with the hydrometeological and probabilistic characteristics of the storms and winds of typhoons that have been passed through the Korea peninsula during the last twenty-three years since 1961. The paths and intensities of the typhoons were analyzed. Fifty weather stations were selected and the rainfall and wind data during typhoon periods were collected. Rainfall data were analyzed for the patterns and probabilistic distributions. The results were presented to describe the areal distributions of probabilistic characteristics. Wind data were also analysed for their probabilistic distributions. The results obtained from this study can be summarized as follows: 1. The most frequent typhoon path that have passed through the Korean peninsula was type E, which was followed by types CWE, W, WE, and S. The most frequent typhoon intensity was type B, that was followed by A, super A, and C types, respectively. 2. The third quartile typhoon rainfall patterns appear most frequently followed by the second, first, and quartiles, respectively, in Seoul, Pusan, Taegu, Kwangju and Taejon. The single typhoon rainfalls with long rainfall durations tended to show delayed type rainfall patterns predominantly compared to the single rainfalls with short rainfall durations. 3. The most frequent probabilistic distribution for typhoon rainfall event is Pearson type-III, followed by Two-parameter lognormal distribution, and Type-I extremal distribution. 4. The most frequent probability distribution model of seashore location was Pearson type-III distribution. The most frequent probability distribution model of inland location was two parameter lognormal distribution. 5. The most frequent probabilistic distribution for typhoon wind events was Type-I xtremal distribution, followed by Two-parameter lognormal distribution, and Normal distribution.

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Relationships Between the Spatial Distribution of Vegetation and Microenviromnent in a Temperate Hardwood Forest in Mt. Jrnbong Biosphere Reserve Area, Korea (점봉산 생물권 보전지역내 온대낙엽수림에서 미소환경요인과 식생요인의 공간분포와 상관 분석)

  • Lee, Kyu-Song;Cho, Do-Soon
    • The Korean Journal of Ecology
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    • v.23 no.3
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    • pp.241-253
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    • 2000
  • The degree to which microenvironmental factors are linked to spatial patterns of vegetational factors within ecosystems has important consequences for our understanding of how ecosytems are structured and for conservation of rare species in ecosystems. We studied this relationships between the spatial patterns of microenvironmental factors and vegetational factors in temperate hardwood forest in Mt. Jumbong Biological Reserve Area, Korea. To do this, environmental and vegetational factors from 196 micropoints in a 0.49 ha plot were investigated. Most of all environmental factors and vegetational factors showed the variations among micropoints. Microtopographic factors, litter depth, soil moisture content and relative light intensity at this site were spatially dependent at a scale of 14∼62 m. Coverage of tree and shrub layer and species diversity of herb layer in autumn were spatially dependent at a scale of < 15 m. Species richness and species diversity of herb layer in spring and species richness of herb layer in autumn were spatially dependent at a scale of 28∼48 m. Multiple regression analysis showed that spatial patterns of species richness and species diversity of herb layer in spring and autumn were affected by litter depth, slope, subtree layer, shrub, Sasa borealis etc. The best predictor for the spatial patterns of species richness and species diversity of herb layer at this site was the spatial pattern of litter depth. Species richness and species diversity of herb layer showed strongly negative correlation with litter depth. We estimate that the spatial pattern of litter depth at this site were affected by direction of wind, microtopography and spatial pattern of shrub layer.

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A Spatial Analysis on the Formation and Dissolution of Start-up Firms in the Seoul Metropolitan Region (수도권 창업기업의 생멸에 대한 공간분포 패턴 분석)

  • Yi, Chang-Hyo
    • Journal of Cadastre & Land InformatiX
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    • v.45 no.1
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    • pp.241-256
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    • 2015
  • The purpose of this paper is to verify the spatial distribution difference between formation and dissolution of start-up firms related to life-cycle. For this purpose, a Korean business directories and information on business closures were used, and location information, starting time, and closure time of start-up firms in the Seoul metropolitan region from 2007 to 2009 were generated in this study. It applied The spatial distribution analysis methods on the formation and dissolution of the start-up firms included Barcki measurements and global spatial autocorrelation. The total number of start-up firms was 5,810, and their five-year survival rate was 77.25%. The dissolution pattern of the start-up firms was dispersed more than their formation pattern in each of the Seoul metropolitan regions, the city of Seoul, and the city of Incheon-Gyeonggi province. In addition, differences between the formation and dissolution patterns according to size and industry category of the firms were confirmed.

An Analysis of Spatial Characteristics of Environmental-Friendly Certified Farms - Focused on Jeollanam-do - (친환경 인증 농경지의 공간적 특성 분석 - 전라남도를 대상으로 -)

  • Park, Yujin;Gu, Jeong-Yoon;Lee, Sang-Woo;An, Kyungjin;Choi, Jinah;Kim, Sangbum;Park, Se-Rin
    • Journal of Korean Society of Rural Planning
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    • v.29 no.3
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    • pp.79-89
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    • 2023
  • As the demand for environmental-friendly agricultural products continues to rise due to increased concerns regarding food safety and ecosystem conservation, it is becoming important to identify regions and spatial locations where environmental-friendly should be intensively established for production integration. This study aims to analyze the spatial distribution of environmental-friendly certified farms in Jeollanam-do, South Korea. Spatial statistical analysis based on Local Moran's I and Getis-Ord Gi* were used to identify spatial cluster characteristics and landscape indices were utilized to analyze spatial patterns of environmental-friendly certified farms. The results indicated that Haenam-gun, Gangjin-gun, Muan-gun, and Jindo-gun were identified as hotspots, while Muan-gun, Goheung-gun, and Jindo-gun exhibited high connectivity. This suggests that environmental-friendly certified farms in Muan-gun and Jindo-gun were clustered and closely connected to one another. Based on the results of the spatial distribution of environmental-friendly certified farms, areas belonging to the hotspot and with high connectivity should be managed as clustered districts to secure the foundation and system of environmental-friendly certified farms. Areas that belong to cold spots and have low connectivity should be preceded by measures to promote conversion to environmental-friendly agriculture. In addition, it is necessary to make it possible to create a large-scale cluster district through a long-term spatial planning strategy to expand the environmental-friendly certified farms. The findings of this study can provide quantitative data on policies and discussions for developing a model for rural spatial planning.