• Title/Summary/Keyword: Spatial scale

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Automatic Registration of High Resolution Satellite Images using Local Properties of Tie Points (지역적 매칭쌍 특성에 기반한 고해상도영상의 자동기하보정)

  • Han, You-Kyung;Byun, Young-Gi;Choi, Jae-Wan;Han, Dong-Yeob;Kim, -Yong-Il
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.28 no.3
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    • pp.353-359
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    • 2010
  • In this paper, we propose the automatic image-to-image registration of high resolution satellite images using local properties of tie points to improve the registration accuracy. A spatial distance between interest points of reference and sensed images extracted by Scale Invariant Feature Transform(SIFT) is additionally used to extract tie points. Coefficients of affine transform between images are extracted by invariant descriptor based matching, and interest points of sensed image are transformed to the reference coordinate system using these coefficients. The spatial distance between interest points of sensed image which have been transformed to the reference coordinates and interest points of reference image is calculated for secondary matching. The piecewise linear function is applied to the matched tie points for automatic registration of high resolution images. The proposed method can extract spatially well-distributed tie points compared with SIFT based method.

The Politics of Scale: The Social and Political Construction of Geographical Scale in Korean Housing Politics (스케일의 정치: 한국 주택 정치에서의 지리적 스케일의 사회적.정치적 구성)

  • Ryu, Yeon-Taek
    • Journal of the Korean Geographical Society
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    • v.42 no.5
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    • pp.691-709
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    • 2007
  • This paper investigates the social and political construction of geographical scale in conjunction with Korean housing politics. Recently, attention has been drawn to the issue of the social and political construction of geographical scale. Spatial scales have increasingly been regarded as socially constructed and politically contested rather than ontologically pregiven or fixed. The scale literature has paid attention to how different spatial scales can be used or articulated in social movements, with an emphasis on 'up-scaling' and 'scales of activism' rather than 'down-scaling' and 'scales of regulation.' Furthermore, the scale literature has focused on the aspect of empowerment. However, it is worthwhile to examine how scale-especially 'down-scaling' and 'scales of regulation'-can be used not only for marginalizing or excluding unprivileged social groups, but also for controlling the (re)production of space, including housing space. Under a regulatory regime, the Korean central government gained more control over the (re)production of housing space at geographical multi-scales by means of 'jumping scales,' specifically 'down-scaling.' The Korean central government has increasingly obtained the capacity to 'jump scales' by using not only multiscalar strategies for housing developments, but also taking advantage of various scales of institutional networking among the central and local governments, quasi-governmental institutions, and Chaebols, across the state. Traditionally, scale has been regarded as an analytical spatial unit or category. However, scale can be seen as means of inclusion(and exclusion) and legitimation. Choosing institutions to include or exclude cannot be separated from the choices and range of spatial scale, and is closely connected to 'scale spatiality of politics.' Facilitating different forms of 'scales of regulation,' the Korean central government included Chaebols and upper- and middle-income groups for the legitimization of housing projects, but excluded local-scale grassroots organizations and unprivileged social groups as decision-makers.

MODIS AEROSOL RETRIEVAL IN FINE SPATIAL RESOLUTION FOR LOCAL AND URBAN SCALE AIR QUALITY MONITORING APPLICATIONS

  • Lee, Kwon-Ho;Kim, Young-Joon
    • Proceedings of the KSRS Conference
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    • 2005.10a
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    • pp.378-380
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    • 2005
  • Remote sensing of atmospheric aerosol using MODIS satellite data has been proven to be very useful in global/regional scale aerosol monitoring. Due to their large spatial resolution of $10km^2$ MODIS aerosol optical thickness (AOT) data have limitations for local/urban scale aerosol monitoring applications. Modified Bremen Aerosol Retrieval (BAER) algorithm developed by von Hoyningen-Huene et al. (2003) and Lee et al. (2005) has been applied in this study to retrieve AOT in fe resolutions of $500m^2$ over Korea. Look up tables (LUTs) were constructed from the aerosol properties based on sun-photometer observation and radiation transfer model calculations. It was found that relative error between the satellite products and the ground observations was within about $15\%$. Resulting AOT products were correlated with surface PMIO concentration data. There was good correlation between MODIS AOT and surface PM concentration under certain atmospheric conditions, which supports the feasibility of using the high-resolution MODIS AOT for local and urban scale air quality monitoring

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Design and Implementation of a Hybrid Spatial Reasoning Algorithm (혼합 공간 추론 알고리즘의 설계 및 구현)

  • Nam, Sangha;Kim, Incheol
    • Journal of KIISE
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    • v.42 no.5
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    • pp.601-608
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    • 2015
  • In order to answer questions successfully on behalf of the human contestant in DeepQA environments such as 'Jeopardy!', the American quiz show, the computer needs to have the capability of fast temporal and spatial reasoning on a large-scale commonsense knowledge base. In this paper, we present a hybrid spatial reasoning algorithm, among various efficient spatial reasoning methods, for handling directional and topological relations. Our algorithm not only improves the query processing time while reducing unnecessary reasoning calculation, but also effectively deals with the change of spatial knowledge base, as it takes a hybrid method that combines forward and backward reasoning. Through experiments performed on the sample spatial knowledge base with the hybrid spatial reasoner of our algorithm, we demonstrated the high performance of our hybrid spatial reasoning algorithm.

Effect of Dynamic Trunk Equilibrium Exercise on Neglect, Balance, Activities of Daily Living in Stroke Patients With Hemi-Spatial Neglect (편측무시를 가진 뇌졸중 환자를 위한 동적 체간 평형 훈련이 편측무시, 균형, 일상생활수행능력에 미치는 효과)

  • Kang, Tae-woo;Oh, Duck-won
    • Physical Therapy Korea
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    • v.25 no.2
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    • pp.30-43
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    • 2018
  • Background: Hemispatial neglect is defined as the failure to attend, report, respond, or orient toward meaningful stimuli provided in the contralateral side of a brain lesion. Objects: This study was conducted to find out the effect of dynamic trunk equilibirum exercise for stroke patients with hemi-spatial neglect. Methods: This study included 21 stroke subjects, randomly assigned to either the experimental group or the control group. The exercise program consisted of 5 sessions of 20 minutes per week during 4 weeks. The line-bisection test, the Albert test, the balance function score, the Berg balance scale, the postural assessment scale for stroke and the modified Barthel index were measured before and after training. All data were analyzed using SPSS 12.0 for Windows. Between-group and within-group comparison was analyzed by using Independent t-test and Paired t-test respectively. Results: The results of study were as follows: There were significant differences between before and after intervention in both group (p<.05). There were significant differences in the line-bisection test, Albert test, balance function score, Berg balance scale, postural assessment scale for stroke and modified Barthel index between the experimental group and the control group (p<.05). Conclusion: Dynamic trunk equilibrium exercise had a positive effect on patients' neglect, balance ability and activities of daily living. Further studies are required to generalize the results of this study.

A Comprehensive Representation Model for Spatial Relations among Regions and Physical Objects considering Property of Container and Gravity (Container 성질과 중력을 고려한 공간과 객체의 통합적 공간관계 표현 모델)

  • Park, Jong-Hee;Lim, Young-Jae
    • Journal of KIISE:Software and Applications
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    • v.37 no.3
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    • pp.194-204
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    • 2010
  • A space, real or virtual, comprises regions as its parts and physical objects residing in them. A coherent and sophisticated representaion scheme for their spatial relations premises the precision and plausibility in its associated agents' inferencing on the spatial relations and the development of events occurring in such a space. The existing spatial models are not suitable for a comprehensive representation of the general spatial relations in that they have limited expressive powers based on the dichotomy between the large and small scales, or support only a small set of topological relations. The representaion model we propose has the following distinctive chracteristics: firstly, our model provides a comprehensive representation scheme to accommodate large and small scale spaces in an integrated fashion; secondly, our model greatly elaborated the spatial relations among the small-scale objects based on their contact relations and the compositional relations among their respective components objects beyond the basic topological relations like disjoint and touch; thirdly, our model further diversifies the types of supported relations by adding the container property besides the soildness together with considering the gravity direction. The resulting integrated spatial knowledge representation scheme considering the gravity allows the diverse spatial relations in the real world to be simulated in a precise manner in relation to the associated spatial events and provides an expression measure for the agents in such a cyber-world to capture the spatial knowledge to be used for recognizing the situations in the spatial aspects.

Changes of Drainage Paths Length and Characteristic Velocities in Accordance with Spatial Resolutions (공간해상도에 따른 배수경로길이 및 특성유속의 변화)

  • Choi, Yong-Joon;Kim, Joo-Cheol
    • Journal of Korean Society for Geospatial Information Science
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    • v.19 no.3
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    • pp.107-114
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    • 2011
  • In this study, when interpreting leakage using the concept of geographical dispersion based on grid, to choose an appropriate spatial resolution, the statistical characteristics of drainage path length and the pattern of change of hydrodynamic parameters have been observed. Drainage path length has been calculated using an 8-direction algorithm from digital elevation model, from which the hydrodynamic parameters of the watershed were estimated. The scales of topographical map for this analysis are 1:5,000 and 1:25,000, appling grid sizes 5, 10, 15, 20 m and 20, 30, 50, 100, 150, 200 m, respectively. As results of this analysis, depending on the scale of stream networks, the statistical characteristics of drainage path length by spatial resolution and hydrodynamic parameters of the watershed have been changed. Based on the above results, when interpreting leakage using the concept of the geographical dispersion based on grid, in the case of 1:5,000 scale topographical map, a spatial resolution of 5 m will be better showing geographical and hydrodynamic characteristics to apply to the well developed stream network in basins, spatial resolution of 5~20 m to the less developed stream network in basins. And in the case of 1:25,000 scale topographical map, spatial resolution below 50 m is more desirable to show above two characteristics to apply to both cases.

Agglomeration Economies and Intra-metropolitan Location of Firms: A Spatial Analysis on Chicago and Seoul (집적경제와 도시내 기업입지에 대한 공간분선: 서울과 시카고를 대상으로)

  • Jungyul Sohn
    • Journal of the Korean Geographical Society
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    • v.36 no.5
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    • pp.561-577
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    • 2001
  • Urban spatial structure is closely related to the spatial distribution of urban economic activities. The spatial distribution pattern is no more than an aggregated expression of the location and/or relocation behavior of individual firms and establishments. In this respect, it is important to identify and examine the factors that affect the spatial behavior of individual firms for a more comprehensive understanding of urban space. Agglomeration economies are one of the most prominent urban economic phenomena in the modern metropolitan area. Most firms in an urban space seek external economies through the spatial clustering of their activities. Agglomeration economies feature prominently in the analysis of urban economic structure across urban areas. While the agglomeration economies between cities focus at the macro-scale of analysis, such economies within any given city focus more on the micro geographical scale. There have been a number of researches on agglomeration economies, among which there are relatively few approaches based on an intra-urban context. This proper explores the agglomeration economies at the micro scale and tries to reseal the spatial realization of the agglomeration economies within and between sectors. Three sectors are considered in the analysis; manufacturing, retail and service. The model is based on simultaneous equation systems combined with spatially weighted variables and estimated by the KRP estimators.

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A Study on the Spatial Mismatch between the Assessed Land Value and Housing Market Price: Exploring the Scale Effect of the MAUP (개별공시지가와 주택실거래가의 공간적 불일치에 관한 연구: 공간 단위 임의성 문제(MAUP)의 스케일 효과 탐색)

  • Lee, Gunhak;Kim, Kamyoung
    • Journal of the Korean Geographical Society
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    • v.48 no.6
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    • pp.879-896
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    • 2013
  • The assessed land values and housing prices have been widely utilized as a basic information for the land and house trades and for evaluating governmental and local taxes. However, there exists a price difference in actual markets between the assessment level and assessed land values or housing prices. This paper emphasizes the spatial mismatch between the assessed land values and housing market prices and particularly addresses the following two aspects by focusing on spatial effects of the modifiable areal units, which would substantially affect the estimation of the assessed land values and housing prices. First, we examine the spatial distributions of the assessed land values and housing market prices, and the gap between those prices, on the basis of the aggregated spatial units(i.e., aggregation districts). Second, we explore the scale effect of the MAUP(modifiable areal unit problem) generally embedded in estimating the prices of the sampled standard lands and houses, and calibrating the correction index for the land values and housing prices for the individuals. For the application, we analysed the land values and housing prices in Seoul utilizing GIS and statistical software. As a result, some spatial clusters that the housing market prices are significantly higher than the assessed land values were identified at a finer geographic level. Also, it was empirically revealed that the statistical results from the regression of regional variables on the assessed land values for the individuals are significantly affected by the aggregation levels of the spatial units.

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A Model to Support Spatial Decision Making for Selection of Ecotourism Sites in Urban and Regional Area (도시 및 지역의 생태관광지 선정을 위한 공간의사결정지원 평가모델)

  • Lee, Gwan-Gyu
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.12 no.2
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    • pp.50-60
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    • 2009
  • A spatial decision making process is needed when a local government tries to make polices and plans for eco-tourism in urban and regional site scale. This study aimed to suggest an assessment model to support spatial decision making on planning and making polices for eco-tourism. The model composes 6 stages of 'setting up ecogeographic territories'. 'value analysis method as ecotourism resources' 'synthetic assessing', 'grading values', 'selecting main resources for ecotourism' and 'spatial decision making support'. Applying the model to Shiheung city in Kyounggi province, validity was secured. By using the model, it was possible to make some decisions effectively such as selection of ecotourism resources, decision of the priorities of polices for ecotourism, and setting up the type of ecotourism to be introduced. In addition, by visualizing high valued resources and areas for ecotourism it w possible to support to make plans and policies effectively.