• Title/Summary/Keyword: Spatial point pattern analysis

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Analysis of Changes in the Population Potential of the Neighboring Areas of Sejong City Using the Accessibility Model (Accessibility 모델을 활용한 세종시 인접 지역의 인구잠재력 변화 분석)

  • Kim, Ho-Yong;Yun, Jeong-Mi
    • Journal of the Korean Association of Geographic Information Studies
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    • v.17 no.4
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    • pp.167-178
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    • 2014
  • As large-scale housing sites are being developed rapidly in Sejong City, which was launched in 2012 for resolving the adverse effects of overconcentration in the capital area, promoting balanced development of the country, and reinforcing national competitiveness, changes in spatial structure are expected in the surrounding areas. For setting the directions of urban planning, it is essential to understand changes in spatial structure. This study purposed to measure changes in the spatial structure of neighboring areas resulting from the construction of Sejong City by approaching from the aspect of spatial interaction. In the analysis, we calculated population potential for future spatial interaction using the accessibility model, and interpreted quantitatively and qualitatively the outcomes of spatial interaction among neighboring areas before and after the construction of Sejong City using population potential as an indicator. According to the results of the analysis, the impact range of the population potential of the subject areas had been shrinking continuously since 1995, and in 2013 population potential dispersed as the population concentrated on and around Cheonan City. Although Sejong City, as a new area of population potential, was not found to play the role of a pivotal point for the surrounding areas, it is probably because the analysis was made just after people began to move to Sejong City. Accordingly, along with the effort of Sejong City to reach the planned population, it is necessary to keep monitoring changes in related factors and changes in the spatial structure of the surrounding cities resulting from the growth of population.

Shoppers' Shopping Path Pattern Analysis using RFID Data (RFID 데이터를 이용한 고객 쇼핑 동선 패턴 분석)

  • Yang, Seungjoon;Jung, In-Chul;Kwon, Young S.
    • Journal of Information Technology Services
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    • v.11 no.sup
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    • pp.61-74
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    • 2012
  • As the retail industry has been challenged by stiff competition, the retailer becomes more interested in better understanding consumers' in-store behavior to gain and sustain competitive advantage. Consumers' shopping paths provide valuable clues to understanding customers' in-store behavior, which has been a long standing research issue in business. This study is to explore the shopping path patterns in a grocery using RFID technology and clustering method. To this end, we designed the RFID systems, affixing active RFID tags to the bottom of grocery carts. The tag emit signal that is received by receptors installed at various location throughout the store. The RFID systems provide the time and location of the cart while consumers shop around the store. The point of sale data are matched with the cart movement records to provide a complete picture of each shopping path. To find the distinctive patterns of consumers' shopping paths, we proposed the distance-index matrix using dijkstra method and normalization method to conduct the clustering in order to handle the problem in measuring the similarity among shopping paths, which is raised by the spatial nature of consumer movement in a grocery. After analyzing the RFID data obtained in one of the groceries in a major Korean retailer, we could successfully identify several distinctive patterns of shopping paths, which prove to provide the valuable implications for store management.

An Alternative Method for Assessing Local Spatial Association Among Inter-paired Location Events: Vector Spatial Autocorrelation in Housing Transactions (쌍대위치 이벤트들의 국지적 공간적 연관성을 평가하기 위한 방법론적 연구: 주택거래의 벡터 공간적 자기상관)

  • Lee, Gun-Hak
    • Journal of the Economic Geographical Society of Korea
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    • v.11 no.4
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    • pp.564-579
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    • 2008
  • It is often challenging to evaluate local spatial association among onedimensional vectors generally representing paired-location events where two points are physically or functionally connected. This is largely because of complex process of such geographic phenomena itself and partially representational complexity. This paper addresses an alternative way to identify spatially autocorrelated paired-location events (or vectors) at a local scale. In doing so, we propose a statistical algorithm combining univariate point pattern analysis for evaluating local clustering of origin-points and similarity measure of corresponding vectors. For practical use of the suggested method, we present an empirical application using transactions data in a local housing market, particularly recorded from 2004 to 2006 in Franklin County, Ohio in the United States. As a result, several locally characterized similar transactions are identified among a set of vectors showing various local moves associated with communities defined.

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An Empirical Study on the Correlation between TOD Planning Elements and Subway Ridership in Busan Metropolitan City (부산시 역세권 TOD계획요소의 공간특성과 지하철 이용객 수의 상관성에 관한 실증연구)

  • Choi, Don-Jeong;Suh, Yong-Cheol
    • Journal of the Korean Association of Geographic Information Studies
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    • v.17 no.3
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    • pp.147-159
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    • 2014
  • Public transportation ridership and walkability of urban district can be enhanced through high quality of TOD(Transit Oriented Development) elements. Generally, TOD have been evaluated several physical components such as the diversity of land use pattern, accessibility of public transportation and aspects of urban design around the station area. Especially, Spatial characteristics of TOD planning elements have many potential dependent when considering the characteristics of Rail Station-Influenced Area Development which is performing around subway station. Therefore, researchers should be considering the variation of spatial properties for planning elements according the set of spatial area and their socioeconomic factors. However, existing many cases related TOD does not consider about this point. In this paper, the changes of TOD characteristics were analyzed by different spatial units surrounding subway station in Busan Metropolitan City. Multiple Regression Analysis was performed for an investigation of effective spatial unit of TOD planning elements in this area using subway ridership data. In addition, the application validity of socioeconomic variables was examined through a comparative analysis of regression results with the multiple regression that implied only physical TOD elements. As the result, the variation of spatial properties for TOD planning elements according to the set of spatial unit was found. Furthermore, the specific spatial unit to applicable TOD elements in this area was derived. And the multiple regression model which added socioeconomic variables was derived more improved estimate results than the multiple regression model that implied only physical TOD elements.

Deformation and failure mechanism exploration of surrounding rock in huge underground cavern

  • Tian, Zhenhua;Liu, Jian;Wang, Xiaogang;Liu, Lipeng;Lv, Xiaobo;Zhang, Xiaotong
    • Structural Engineering and Mechanics
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    • v.72 no.2
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    • pp.275-291
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    • 2019
  • In a super-large underground with "large span and high side wall", it is buried in mountains with uneven lithology, complicated geostress field and developed geological structure. These surrounding rocks are more susceptible to stability issues during the construction period. This paper takes the left bank of Baihetan hydropower station (span is 34m) as a case study example, wherein the deformation mechanism of surrounding rock appears prominent. Through analysis of geological, geophysical, construction and monitoring data, the deformation characteristics and factors are concluded. The failure mechanism, spatial distribution characteristics, and evolution mechanism are also discussed, where rock mechanics theory, $FLAC^{3D}$ numerical simulation, rock creep theory, and the theory of center point are combined. In general, huge underground cavern stability issues has arisen with respect to huge-scale and adverse geological conditions since settling these issues will have milestone significance based on the evolutionary pattern of the surrounding rock and the correlation analyses, the rational structure of the factors, and the method of nonlinear regression modeling with regard to the construction and development of hydropower engineering projects among the worldwide.

Wavelet Compression Experiments of the Remotely Sensed Images for Three Kinds of Wavelet Families

  • Jin, Hong-Sung;Han, Dong-Yeob
    • Spatial Information Research
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    • v.17 no.4
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    • pp.455-462
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    • 2009
  • A method to find the nearly optimal PSNR values for compression was tried to remotely sensed images. There is no rule to find the best wavelet pairs for image processing. The expected wavelet pairs following the suggested algorithm showed the optimal result for various kinds of images. Firstly, the PSNR variations with three wavelet families were analyzed. In many cases the longer wavelet filter shows the higher PSNR value, but the rate is getting less in orthogonal wavelet families. Wavelets with moderate filter length are suggested at the point of computational cost. For biorthogonal families it was hard to predict from the length of filters. Multiresolution wavelet analysis was used up to level 3 with three kinds of wavelet families. Biorthogonal wavelet family showed irregular pattern to get the maximum PSNR values, while orthogonal wavelet families showed regular pattern. In orthogonal wavelet families the nearly optimal wavelet pair can be predicted from the level 1.

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Biotic and spatial factors potentially explain the susceptibility of forests to direct hurricane damage

  • Kim, Daehyun;Millington, Andrew C.;Lafon, Charles W.
    • Journal of Ecology and Environment
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    • v.43 no.4
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    • pp.364-375
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    • 2019
  • Background: Ecologists continue to investigate the factors that potentially affect the pattern and magnitude of tree damage during catastrophic windstorms in forests. However, there still is a paucity of research on which trees are more vulnerable to direct damage by winds rather than being knocked down by the fall of another tree. We evaluated this question in a mixed hardwood-softwood forest within the Big Thicket National Preserve (BTNP) of southeast Texas, USA, which was substantially impacted by Hurricane Rita in September 2005. Results: We showed that multiple factors, including tree height, shade-tolerance, height-to-diameter ratio, and neighborhood density (i.e., pre-Rita stem distribution) significantly explained the susceptibility of trees to direct storm damage. We also found that no single factor had pervasive importance over the others and, instead, that all factors were tightly intertwined in a complex way, such that they often complemented each other, and that they contributed simultaneously to the overall susceptibility to and patterns of windstorm damage in the BTNP. Conclusions: Directly damaged trees greatly influence the forest by causing secondary damage to other trees. We propose that directly and indirectly damaged (or susceptible) trees should be considered separately when assessing or predicting the impact of windstorms on a forest ecosystem; to better predict the pathways of community structure reorganization and guide forest management and conservation practices. Forest managers are recommended to adopt a holistic view that considers and combines various components of the forest ecosystem when establishing strategies for mitigating the impact of catastrophic winds.

A Study on the Deriving of Areas of Concern for Crime using the Mental Map (멘탈 맵을 이용한 범죄발생 우려 지역 도출에 관한 연구)

  • Park, Su Jeong;Shin, Dong Bin
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.37 no.3
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    • pp.177-188
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    • 2019
  • Recently, citizens are feeling anxious as 'Motiveless Crime' increases. The quality of citizens life is degraded and the degree of crime fear is increasing. In this study, based on various variables related to crime other than actual crime occurrence status, crime occurrence points (point line polygon) felt by citizens are created by using mental map methodology. And the purpose of this study is to derive the area of concern for crime through spatial overlap analysis using kernel density estimation analysis. It also uses spatial overlay analysis using kernel density estimation to derive areas of concern for crime occurrence. As a result, the local residents' request point and the areas of concern for crime were overlapped. In addition, the mental map indicating the fear of crime was constructed by mapping mainly the areas between the facilities, the non-construction area such as the narrow area, the security CCTV, the streetlight. This study is meaningful in that it tried to derive a crime occurrence concern area by using mental map method unlike the previous study related to crime. The results of this study, such as mental map, could be used in various fields such as construction of fragile crime map, guideline of crime prevention through environment design.

Landscape Ecological Analysis of Coastal Sand Dune Ecosystem in Korea (해안사구생태계의 경관생태분석)

  • Kim, Jae-Eun;Hong, Sun-Kee
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.12 no.3
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    • pp.21-32
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    • 2009
  • Coastal sand dune area is the important ecosystem as an ecotone which located between coastal area and terrestrial area. Moreover, it is very complicate landscape that have geomorphological interaction between erosion and accumulation of sand. Therefore, it is necessary to understand the sand dune ecosystem in view point of landscape scale including background landscape affecting origin of sand dune. Landscape ecological approach in the complicate ecosystem already started in developed countries, and it is applied to land management and biodiversity conservation strategies even in national scale. In this paper, landscape ecological analysis using landscape pattern analysis was carried out on 7 study areas (Yellow Sea : Hakampo and Doksan, South Sea : Namyeol and Balpo, East Sea : Hosan, Hupo and Goraebul) in Korean coastal sand dune ecosystem. Landscape elements were composed by 9 elements in these study areas. Major background landscape elements was the forest land and agricultural field. Namyeol (S06) has larger patch landscape compare to other areas. In patch shape indices, Hupo (E10) shows more complicate patch shapes. The high landscape heterogeneity showed in the Doksan sand dune area and that of Hosan. It shows that these areas were composed by various patch types. However, using landscape indices have to use very carefully because several variables have influence to the result such as scale and spatial pattern of study areas. Although landscape analysis through landscape indices shows sometimes difficult to explain the ecosystem, landscape scale approach on ecosystem assessment still useful to interpret in ecological process in large range of habitat.

Future drought assessment in the Nakdong basin in Korea under climate change impacts

  • Kim, Gwang-Seob;Quan, Ngo Van
    • Proceedings of the Korea Water Resources Association Conference
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    • 2012.05a
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    • pp.458-458
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    • 2012
  • Climate extreme variability is a major cause of disaster such as flood and drought types occurred in Korea and its effects is also more severe damage in last decades which can be danger mature events in the future. The main aim of this study was to assess the effectives of climate change on drought for an agriculture as Nakdong basin in Korea using climate change data in the future from data of General Circulation Models (GCM) of ECHO-G, with the developing countries like Korea, the developed climate scenario of medium-high greenhouse gas emission was proposed of the SRES A2. The Standardized Precipitation Index (SPI) was applied for drought evaluation. The drought index (SPI) applied for sites in catchment and it is evaluated accordingly by current and future precipitation data, specific as determined for data from nine precipitation stations with data covering the period 1980-2009 for current and three periods 2010-2039, 2040-2069 and 2070-2099 for future; time scales of 3month were used for evaluating. The results determined drought duration, magnitude and spatial extent. The drought in catchment act intensively occurred in March, April, May and November and months of drought extreme often appeared annual in May and November; drought frequent is a non-uniform cyclic pattern in an irregular repetitive manner, but results showed drought intensity increasing in future periods. The results indicated also spatial point of view, the SPI analysis showed two of drought extents; local drought acting on one or more one of sites and entire drought as cover all of site in catchment. In addition, the meteorology drought simulation maps of spatial drought representation were carried out with GIS software to generate for some drought extreme years in study area. The method applied in this study are expected to be appropriately applicable to the evaluation of the effects of extreme hydrologic events, the results also provide useful for the drought warning and sustainable water resources management strategies and policy in agriculture basins.

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