• Title/Summary/Keyword: Urban size

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A Time-Series Analysis of Landscape Structural Changes using the Spatial Autocorrelation Method - Focusing on Namyangju Area - (공간자기상관분석을 통한 시계열적 경관구조의 변화 분석 - 남양주지역을 대상으로 -)

  • Kim, Heeju;Oh, Kyushik;Lee, Dongkun
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.14 no.3
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    • pp.1-14
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    • 2011
  • In order to determine temporal changes of the urban landscape, interdependence and interaction among geo-spatial objects can be analyzed using GIS analytic methods. In this study, to investigate changes in the landscape structure of the Namyangju area, the size and shape of landscape patches, and the distance between the patches were analyzed with the Spatial Autocorrelation Method. In addition, both global and local spatial autocorrelation analyses were conducted. The results of global Moran's I revealed that both patch size and shape index transformed to a more dispersed pattern over time. Next, the local Moran's I of patch size in all time series determined that almost all patches were of a high-low pattern. Meanwhile, the local Moran's I of the shape index was found to have changed from a high-high pattern to a high-low pattern in time series. Finally, as time passes, the number of hot spot patches about size and shape index had been decreased according to the results of hot spot analysis. These changes appeared around the development projects in the study area. From the results of this study, degradation of landscape patches in Namyangju were ascertained and their specific areas were delineated. Such results can be used as useful data in selecting areas for conservation and for preparing plans and strategies in environmental restoration.

Effect of Building Generalization in a Lattice Cell Form on the Spatial Connectivity of Overland Storm Waterways in an Urban Residential Area (격자형 건물 일반화가 도시 주거지 빗물 유출경로의 연속성에 미치는 영향)

  • JEON, Ka-Young;HA, Sung-Ryong
    • Journal of the Korean Association of Geographic Information Studies
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    • v.20 no.1
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    • pp.137-151
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    • 2017
  • The space between urban buildings becomes a waterway during rain events and requires a boundary condition in numerical calculations on grids to separate overland storm flows from building areas. Minimization of the building data distortion as a boundary condition is a necessary step for generating accurate calculation results. A building generalization is used to reduce the distortion of building shapes and areas during a raster conversion. The objective of this study was to provide the appropriate threshold value for building generalization and grid size in a numerical calculation. The impact of building generation on the connectivity of urban storm waterways were analyzed for a general residential area. The building generalization threshold value and the grid size for numerical analysis were selected as the independent variables for analysis, and the number and area of sinks were used as the dependent variables. The values for the building generalization threshold and grid size were taken as the optimal values to maximize the building area and minimize the sink area. With a 3 m generalization threshold, sets of $5{\times}5m$ to $10{\times}10m$ caused 5% less building area and 94.4% more sink area compared to the original values. Two sites representing general residential area types 2 and 3 were used to verify building generalization thresholds for improving the connectivity of storm waterways. It is clear that the recommended values are effective for reducing the distortion in both building and sink areas.

A Study on Determination of the Matching Size of IKONOS Stereo Imagery (IKONOS 스테레오 영상의 매칭사이즈 결정연구)

  • Lee, Hyo-Seong;Ahn, Ki-Weon;Lee, Chang-No;Seo, Doo-Cheon
    • Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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    • 2007.04a
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    • pp.201-205
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    • 2007
  • In the post-Cold War era, acquisition technique of high-resolution satellite imagery (HRSI) has begun to commercialize. IKONOS-2 satellite imaging data is supplied for the first time in the 21st century. Many researchers testified mapping possibility of the HRSI data instead of aerial photography. It is easy to renew and automate a topographical map because HRSI not only can be more taken widely and periodically than aerial photography, but also can be directly supplied as digital image. In this study matching size of IKONOS Geo-level stereo image is presented lot production of digital elevation model (DEM). We applied area based matching method using correlation coefficient of pixel brightness value between the two images. After matching line (where "matching line" implies straight line that is approximated to complex non-linear epipolar geometry) is established by exterior orientation parameters (EOPs) to minimize search area, the matching is tarried out based on this line. The experiment on matching size is performed according to land cover property, which is divided off into four areas (water, urban land, forest land and agricultural land). In each of the test areas, window size for the highest correlation coefficient is selected as propel size for matching. As the results of experiment, the proper size was selected as $123{\times}123$ pixels window, $13{\times}13$ pixels window, $129{\times}129$ pixels window and $81{\times}81$ pixels window in the water area, urban land, forest land and agricultural land, respectively. Of course, determination of the matching size by the correlation coefficient may be not absolute appraisal method. Optimum matching size using the geometric accuracy therefore, will be presented by the further work.

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Tracer Experiment for the Investigation of Urban Scale Dispersion of Air Pollutants - Simulation by CALPUFF Dispersion Model and Diffusion Feature of Tracer Gases (추적자 확산 실험에 의한 서울 도심 확산 현상 연구 - 추적기체의 확산특징과 CALPUFF 모델에 의한 모사)

  • Lee, Chong-Bum;Kim, Jea-Chul;Lee, Gang-Woong;Ro, Chul-Un;Kim, Hye-Kyeong
    • Journal of Korean Society for Atmospheric Environment
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    • v.23 no.4
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    • pp.405-419
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    • 2007
  • A series of tracer experiments for the evaluation of atmospheric dispersion was performed over the urban area of Seoul using two inert, non-deposition perfluorocarbon (PMCH and m-PDCH) gases during three years campaign on 2002, 2003 and 2005. 30 sampling sites for collecting these tracers were located along two arcs of 2.5 and 5 kilometers downwind from the release point. About ten measurements which each lasted for 2 hours or 4 hours were made over the two consecutive days during each campaign. CALPUFF and MM5 meteorological model were applied to evaluate the urban dispersion in detail. Size of Modeling domain was $27\;km{\times}23\;km$ and the fine nest in the modeling domain had a grid size of 0.5 km. The results showed that CALPUFF dispersion model had a tendency to estimate tracer concentrations about $2{\sim}5$ times less than those of ambient samples under many conditions. These consistent inaccuracy in urban dispersion was attributed to inherent inaccuracy and lack of details in terrain data at urban area.

A Study on Causal Factors of Organizational Commitment of Public Servants in Urban Health Centers: Testing a Hypothetical Canusal Model (도시보건소 공무원의 조직몰입도 인과요인에 관한 연구 - 한 가설적 인과모형분석을 통해 -)

  • 이상준;김창엽;김용익;신영수
    • Health Policy and Management
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    • v.8 no.1
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    • pp.52-96
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    • 1998
  • To find causal factors and improvement plans of organizational commitment of public servants in urban health centers, a hypothetical causal model, which included 2 endogenous variables(organizational commitment & organizational satisfaction) and 15 exogenous variables, was constructed. Exogenous variables consisted of individual factors (sex, age, education, job-grade, and annual salary), psychological variables(pride for organization, extrinsic motivation, intrinsic motivation and support of supervisor) ad structural variables(formalization, centralization, communication, job-conflict, job-decision, and workload). In the hypothetical causal model, organizational commitment was supposed to be effect variable, and organizational satisfaction was presumed to be intervening variable to mediate between organizational commitment and exogenous variables. For data collection, cross-sectional self-administered questionnaire survey was conducted to 1,295 public servants from 32 urban health centers nationwide. The survey responses were from 934, 72.1% of subjects. But 756 responses(58.4%) were analyzed because of excluding ones with missing values. The hypothetical causal model was fitted by covariance structural analysis with maximum likelihood method. Main results were as follows: (1) The fitted causal model accounted for 33 and 55 percent of total variance of organizational commitment and organizational satisfaction of public servants, respectively. (2) In order of effect size, pride for organization, supervisor support, communication, extrinsic motivation and centralization had an indirect effect effect on organizational commitment through organizational satisfaction. However, the effect of centralization was negative. (3) Pride for organiztion, intrinsic motivation, organizational satisfaction, job-conflict, supervisor support, communication, age, centralization, annual salar and extrinsic motivation had indirect or direct effects on organizational commitment in order of effect size. Among them, effects of job-conflict and centraldization were negative. In conclusion, these results suggested that organizational commitment of public servants in urban health centers could be enhanced by pride for organization, intrinsic and extrinsic motivations, prevention of job-conflict and excess centralization, supervisor support and active communication. Especially, pride for organization and intrinsic motivation were expected to play the most important role.

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The Land Use Characteristics and Renewal of Urban Central District in Daegu (대구시 도심 토지이용 특성과 재개발)

  • Lee, Sang-Yool
    • Journal of the Korean association of regional geographers
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    • v.9 no.4
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    • pp.592-607
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    • 2003
  • This study on land use and regeneration of urban central district in Daegu investigates the current trend of those changes, and examines the change of urban core on land use, Since the 1980s, large cities in Korea have experienced the decline of spatial economic activities as well as population. Such urban decline has a relation with land use which can be classified with urban land use district and actual land use. This study tried to capture urban land use in three aspects; downtown business, residence, and the change of land use conversion. Based on land use characteristics, the size of residence land use has played a major role in hindering of the efficiency of land use. Also, this study has reviewed urban renewal projects in Daegu, especially urban core renewal projects, and discussed the problems of the projects.

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Segmentation and Characteristic Analysis of Urban Farmers Behavior (도시농업 활동 유형화 연구)

  • Hwang, Jeong-Im;Choi, Yoon-Ji;Jang, Bo-Gyung;Rhee, Sang-Young
    • The Korean Journal of Community Living Science
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    • v.21 no.4
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    • pp.619-631
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    • 2010
  • The purpose of this study is to segment and examine urban farmers behavior by applying a two-step cluster analysis and multi-nominal logit model. The data were collected by a telephone survey with two-staged stratified random sampling in the cities around the country for the purpose of acquiring representative data. Respondents were asked to describe their awareness of urban agriculture, their agricultural activity, and sociodemographic characteristics. Among 2,000 cases, 381 cases(19.1%) which were of participants in urban agriculture were analysed in SPSS. From the findings, 27.3% of respondents had heard the word 'urban agriculture', and 25.5% of them regarded themselves as urban farmers. Four different clusters were derived from two-step clusters based on motive, place, companion, area and hours. They were 'Large scale hobby farming(cluster 1)', ‘Weekend farm/ hobby farming(cluster 2)', 'Land/ Self-supporting farming(cluster 3)', and 'Small scale hobby farming(cluster 4)'. The result of multinomial logistic regression showed that there were significant differences among these four segmented groups in terms of age, city size and housing type. In other words, there is quite a possibility that urbanites select different urban farming types according to their socio-demographic profiles. Therefore, the urbanite profiles can be used as the basis for promoting policy of several urban agriculture types. According to the result, policy directions for facilitating urban agriculture were presented.

Development and Its Application of Urban Flood Model in Building Area (밀집시가지 침수모형의 개발 및 적용)

  • Kang, Sang-Hyeok;Kim, Kyung-Nam;Han, Dong-Jun;Kim, Jung-Han
    • 한국방재학회:학술대회논문집
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    • 2007.02a
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    • pp.203-206
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    • 2007
  • In urban flood model, the features like roads, buildings, and river's banks have great effect on flow dynamics and flood propagation and it must be accounted for model set-up. Two-dimensional hydraulic models in high-density building areas are at the forefront of current research into flood inundation mechanisms, but they are however constrained by inadequate parameters of topography and friction due to insufficient and inaccurate data. This paper describes the development of urban flooding with the extraction of building areas and estimates the its influence on flood inundation extent, and present initial results of flood simulation varying grid size.

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Planting of Urban Environmental Forest and Community Planting Area (도시환경림 및 군락식재지의 배식 기법 연구)

  • Cho, Woo;Lee, Kuong-Jae
    • Journal of the Korean Institute of Landscape Architecture
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    • v.26 no.1
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    • pp.70-82
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    • 1998
  • The purpose of this study was to propose the community planting method through analyzing the plant community structure of three green space types and the relationship of vegetation and wild bird inhabitation of urban environmental forest in Seoul, Korea. The results from this study showed that the vegetation stratification, coverage, and species diversity were closely related to the wild bird inhabitation. In addition, the environmental forest in study site was analyzed as a negative factor that may decrease the biodiversity. Therefore the ecological structure and environmental condition must be considered in order to improve the quality of environmental forest. Based on results in three green space types, the planting species, density and species size for proper community planting were proposed in this study. The ecological niche relationships among sixteen selected species were also presented. The results will be provided as an valueable output for the completed community planting of urban green space in the central region, Korea.

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A Study on the Alternative Demand Ranking for Urban Parks in Seoul (도시공원 수요에 관한 행정구역별 우선순위 평가에 관한 연구 - 서울시를 중심으로 -)

  • Koo, Jae-Oh;Seo, Eung-Chul
    • Journal of Industrial Technology
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    • v.7
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    • pp.3-7
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    • 1987
  • The Urban park plays a significant role as an ideal space for residents. In this sense, Seoul city established a criterion for urban park system according to the park size per person in each district of Seoul. However, that criterion tends not to meet the residents behavioral patterns and interaction dynamics between districts. The objective of this study is to establish the demand forecasting of urban park in Seoul. The result of this study shows that the priority of designating park area is changed greatly when interaction dynamics between districts is taken into account.

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