• Title/Summary/Keyword: spatial values

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The Distribution Analysis of PM10 in Seoul Using Spatial Interpolation Methods (공간보간기법에 의한 서울시 미세먼지(PM10)의 분포 분석)

  • Cho, Hong-Lae;Jeong, Jong-Chul
    • Journal of Environmental Impact Assessment
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    • v.18 no.1
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    • pp.31-39
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    • 2009
  • A lot of data which are used in environment analysis of air pollution have characteristics that are distributed continuously in space. In this point, the collected data value such as precipitation, temperature, altitude, pollution density, PM10 have spatial aspect. When geostatistical data analysis are needed, acquisition of the value in every point is the best way, however, it is impossible because of the costs and time. Therefore, it is necessary to estimate the unknown values at unsampled locations based on observations. In this study, spatial interpolation method such as local trend surface model, IDW(inverse distance weighted), RBF(radial basis function), Kriging were applied to PM10 annual average concentration of Seoul in 2005 and the accuracy was evaluated. For evaluation of interpolation accuracy, range of estimated value, RMSE, average error were analyzed with observation data. The Kriging and RBF methods had the higher accuracy than others.

Reversible data hiding algorithm using spatial locality and the surface characteristics of image

  • Jung, Soo-Mok;On, Byung-Won
    • Journal of the Korea Society of Computer and Information
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    • v.21 no.8
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    • pp.1-12
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    • 2016
  • In this paper, we propose a very efficient reversible data hiding algorithm using spatial locality and the surface characteristics of image. Spacial locality and a variety of surface characteristics are present in natural images. So, it is possible to precisely predict the pixel value using the locality and surface characteristics of image. Therefore, the frequency is increased significantly at the peak point of the difference histogram using the precisely predicted pixel values. Thus, it is possible to increase the amount of data to be embedded in image using the spatial locality and surface characteristics of image. By using the proposed reversible data hiding algorithm, visually high quality stego-image can be generated, the embedded data and the original cover image can be extracted without distortion from the stego-image, and the embedding data are much greater than that of the previous algorithm. The experimental results show the superiority of the proposed algorithm.

The Spatial Disparity of Opportunity Potentials in Korea (한국 도시의 경제 $\cdot$ 문화 $\cdot$ 사회 복지적 기회 잠재력의 지역적 격차)

  • Choi, Yoon-Jeong;Lee, Keumsook
    • Journal of the Economic Geographical Society of Korea
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    • v.8 no.1
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    • pp.91-105
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    • 2005
  • The assessment (or the evaluation) of spatial disparity is the main concern for the study of spatial disparities or spatial inequalities. In order to evaluate the spatial disparity, the regional differences have to be counted quantitatively. Several measurements have been introduced for evaluating the development potentials of each region. Most of them are the composite indices of the socio-economic variables rather than the real potentials of the region. This study attempts to investigate the spatial disparity in Korea. For the purpose, the levels of opportunity potentials of the cities have been calculated by the Potential Model redefined by Lee(1995). The opportunity potentials have been calculated for the educational, cultural, medical service, environmental sectors, income, and consumption sectors, and the spatial patterns of various opportunity potentials have been analyzed. The spatial patterns of opportunity potentials show the severe concentration on the Metropolitan Seoul area through all sectors. The next level concentration appears at the other end of the Keuyng-Bu axis. And the cities relatively high opportunity potential values are distributed along the Keuyng-Bu axis. Remain parts of the country show quietly low opportunity potential values. In particular, the southern-west and the northern-east parts show relatively very low values. This pattern appears for all sectors except for the opportunity potential of the environmental sector. It means that the spatial disparity in Korea have been promoted and enhanced by the national development policies concentrated the investment on the large cities along the Keuyng-Bu axis during the last 40 years.

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Study on the Selection and Application of a Spatial Analysis Model Appropriate for Selecting the Radon Priority Management Target Area (라돈 우선관리 대상 지역 선정에 적합한 공간분석모형의 선정 및 활용에 관한 연구)

  • Nam Goung, Sun Ju;Choi, Kil Yong;Hong, Hyung Jin;Yoon, Dan Ki;Kim, Yoon Shin;Park, Si Hyun;Kim, Yoon Kwan;Lee, Cheol Min
    • Journal of Environmental Health Sciences
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    • v.45 no.1
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    • pp.82-96
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    • 2019
  • Objective: The aims of this study were to provide the basic data for establishing a precautionary management policy and to develop a methodology for selecting a radon management priority target area suitable for the Korean domestic environment. Methods: A suitable mapping method for the domestic environment was derived by conducting a quantitative comparison of predicted values and measured values that were calculated through implementation of two models such as IDW and RBF methods. And a qualitative comparison including the clarity of information transmission of the written radon map was carried out. Results: The predicted and measured values were obtained through the implementation of the spatial analysis models. The IDW method showed the lowest in the calculated mean square error and had a higher correlation coefficient than the other methods. As results of comparing the uncertainty using the jackknife concept and the concept of error distance for comparison of the differences according to the model interpolation method, the sum of the error distances showed a modest increase compared with the RBF method. As a result of qualitatively comparing the information transfer clarity between the radon maps prepared with the predicted values through the model implementation, it was found that the maps plotted using the predicted values by the implementation of the IDW method had greater clarity in terms of highness and lowness of radon concentration per area compared with the maps plotted by other methods. Conclusions: The radon management priority area suggests selecting a metropolitan city including an area with a high radon concentration.

Evaluation Index of Rural Development for Producing Potential Value of Rural Regions on a Commercial Scale (농촌의 잠재적 가치에 의한 농촌지역개발 평가지표 연구)

  • Suh, Kyo;Lee, Ji-Min;Kim, Han-Joong;Jung, Nam-Su;Cho, Soon-Jae;Lee, Jeong-Jae
    • Journal of Korean Society of Rural Planning
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    • v.9 no.1 s.18
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    • pp.47-53
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    • 2003
  • The purpose of this research was to develop evaluation index of regional development for producing potential values of rural regions besides agriculture on a commercial scale. Rural regions have potential values such as preserved nature and spatial advantages and so on. For regional development, potential values should be synthetically evaluated by objective and standard index for supporting decision. For evaluation of plural functions of rural regions, evaluation index of rural regions was developed based on rural amenity. Applicability of evaluation index was studied using GIS and natural break method.

Relationship assessment among land use and land cover and land surface temperature over downtown and suburban areas in Yangon City, Myanmar

  • Yee, Khin Mar;Ahn, Hoyong;Shin, Dongyoon;Choi, Chuluong
    • Korean Journal of Remote Sensing
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    • v.32 no.4
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    • pp.353-364
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    • 2016
  • Yangon city is experienced a rapid urban expansion over the last two decades due to accelerate with the socioeconomic development. This research work studied an investigation into the application of the integration of the Remote Sensing (RS) and Geographic Information System (GIS) for observing Land Use and Land Cover (LULC) patterns and evaluate its impact on Land Surface Temperature (LST) of the downtown, suburban 1 and suburban 2 of Yangon city. The main purpose of this paper was to examine and analyze the variation of the spatial distribution property of the LULC of urban spatial information related with the LST and Normalized Difference Vegetation Index (NDVI) using RS and GIS. This paper was observed on image processing of LULC classification, LST and NDVI were extracted from Landsat 8 Operational Land Imager (OLI) image data. Then, LULC pattern was linked with the variation of LST data of the Yangon area for the further connection of the correlation between surface temperature and urban structure. As a result, NDVI values were used to examine the relation between thermal behavior and condition of land cover categories. The spatial distribution of LST has been found mixed pattern and higher LST was located with the scatter pattern, which was related to certain LULC types within downtown, suburban 1 and 2. The result of this paper, LST and NDVI analysis exhibited a strong negative correlation without water bodies for all three portions of Yangon area. The strongest coefficient correlation was found downtown area (-0.8707) and followed suburban 1 (-0.7526) and suburban 2(-0.6923).

A Study on the Performance Evaluation Method of the Spatial Information Network based on GIS (인터넷 기반의 공간정보유통망 성능분석 방법에 관한 연구)

  • Jin, Heui-Chae;Si, Jong-Yik
    • Journal of Korea Spatial Information System Society
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    • v.1 no.1 s.1
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    • pp.29-37
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    • 1999
  • Recently, brisk up the construction of the spatial information, many people highly concern to tile information circulation of GIS. Each system like GIS has a structure of the information circulation to itself. In this paper, we study on the performance evaluation method of tile structure which to circulate tile spatial information based on the internet. To do this, we hypothesize values of content and scale of the geo-spatial information on each internet network and volumes of the information to circulate between internet networks. Then we suggest a method to evaluate the performance of the structure to aid the circulation of spatial information based on queueing model. Henceforth, with the volumes of data stored and circulated information of each GIS, this method can help to design the structure to circulate the GIS information more efficiently.

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A Study on Spatial and Temporal Distribution Characteristics of Coastal Water Quality Using GIS (GIS를 이용한 연안수질의 시공간적 분포 특성에 대한 연구)

  • Cho, Hong-Lae;Jeoung, Jong-Chul
    • Spatial Information Research
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    • v.14 no.2 s.37
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    • pp.223-234
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    • 2006
  • In order to examine spatio-temporal characteristics of coastal water quality, we applied GIS spatial analysis to the water quality data collected from observation points located on Korean coastal area during 1997$\sim$2004. The water quality parameters measured included: chlorophyll-a, pH, DO, COD, SS, dissolved inorganic nitrogen, dissolved inorganic phosphorous, salinity, temperature. The water quality data used in this paper was obtained only at selected sites even though they are potentially available at any location in a continuous surface. Thus, it is necessary to estimate the values at unsampled locations so as to analyze spatial distribution patterns of coastal water quality, Owing to this reason, we applied IDW(inverse distance weighted) interpolation method to water quality data and evaluated the usefulness of IDW method. After IDW interfolation method was applied, we divided the Korean coastal area into 46 sections and examined spatio-temporal patterns of each section using GIS visualization technique. As a result of evaluation, we can blow that IDW interpolation and GIS are useful for understanding spatial and temporal distribution characteristics of coastal water quality data which is collected from a wide area far many years.

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A Comparison of Neighborhood Definition Methods for Spatial Autocorrelation (공간자기상관 산출을 위한 인접성 정의 방법 비교)

  • Park, Jae-Moon;Hwang, Do-Hyun;Yoon, Hong-Joo
    • Journal of Fisheries and Marine Sciences Education
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    • v.23 no.3
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    • pp.477-485
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    • 2011
  • For the identifying of spatial distribution pattern, Moran's Index(I) which has the range of values from -1 to +1 is common method for the spatial autocorrelation measurement. When I is close to 1, all neighboring features have close to the same value, indicating clustered pattern. Conversely, if the spatial pattern is dispersed, I is close to -1. And I closing to 0 means spatially random pattern. However, this index equation is influenced by how defining the neighboring features for target feature. To compare and understand the difference of neighborhood definition methods, fixed distance neighboring method and Gabriel Network method were used for I. In this study, these two methods were applied to two marine environments with water quality data. One is Gwangyang Bay which has complex geometric coastal structure located in South Sea of Korea. Another is Uljin area adjacent to open sea located in east coast of Korea. The distances between water quality observed locations were relatively regular in Gwangyang Bay, however, irregular in Uljin area. And for the fixed distance method popular Arc GIS tool was used, but, for the Gabriel Network, Visual Basic program was developed to produce Gabriel Network and calculate Moran's I and its Z-score automatically. According to this experimental results, different spatial pattern was showed differently for some data with using of neighboring definition methods. Therefore there is need to choose neighboring definition method carefully for spatial pattern analysis.

A Study on the Index Estimation of Missing Real Estate Transaction Cases Using Machine Learning (머신러닝을 활용한 결측 부동산 매매 지수의 추정에 대한 연구)

  • Kim, Kyung-Min;Kim, Kyuseok;Nam, Daisik
    • Journal of the Economic Geographical Society of Korea
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    • v.25 no.1
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    • pp.171-181
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    • 2022
  • The real estate price index plays key roles as quantitative data in real estate market analysis. International organizations including OECD publish the real estate price indexes by country, and the Korea Real Estate Board announces metropolitan-level and municipal-level indexes. However, when the index is set on the smaller spatial unit level than metropolitan and municipal-level, problems occur: missing values. As the spatial scope is narrowed down, there are cases where there are few or no transactions depending on the unit period, which lead index calculation difficult or even impossible. This study suggests a supervised learning-based machine learning model to compensate for missing values that may occur due to no transaction in a specific range and period. The models proposed in our research verify the accuracy of predicting the existing values and missing values.