• Proceedings of the Korean Association of Geographic Inforamtion Studies Conference
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• 2008.06a
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• pp.477-484
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• 2008

연쇄 살인과 같은 강력 범죄의 심각성이 사회적 이슈가 되면서 이에 대한 효과적인 과학 수사의 필요성이 증가되고 있다. 특히, 연쇄 범죄 데이타에 대한 공간 분석을 통해 범죄자의 거점 위치를 예측하는 지리적 프로파일링과 미래에 발생될 범행 장소의 위치, 즉 기존 범행에 이어 일어날 다음 범행 위치 예측에 관한 연구가 활발하다. 그러나, 이와 관련된 기존 연구는 물리적인 거리에 대한 통계적 기법을 적용하거나 단순한 공간적 분석만을 적용하므로 낮은 예측 정확도를 보이는 문제점이 있다. 본 논문에서는 이러한 문제를 해결하고 보다 효과적인 연쇄 범죄 수사를 지원하는 방법으로써 연쇄 범죄 발생에 대한 공간적 시간적 분포 특성에 따른 시공간 패턴을 기반으로 다양한 시공간 분석을 적용하는 거점 위치 예측 기법과 다음 범행 위치 예측 기법을 제안한다. 제안 기법은 중심축을 따라 나타나는 선형 분포의 연쇄 범죄에서도 정확도 높은 예측이 가능하고, 다수의 서로 다른 군집들에 대해 각 군집내 범행에 대한 지역적 예측과 대상 영역의 모든 범행에 대한 전역적 예측이 가능하다. 또한 방향 패턴을 활용하여 다음 범행 위치 예측 정확도도 개선하였다.

• Proceedings of the Korea Water Resources Association Conference
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• 2010.05a
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• pp.1196-1200
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• 2010

본 논문에서는 지점 강우의 결측치를 추정하기 위해 전통적인 통계학적 내삽기법을 이용한 역거리가중치법(IDWM), 역지수가중치법(IEWM), 상관계수가중치법(CCWM)과 패턴 인식의 일종인 인공신경망(ANN)기법 그리고 시공간적 강우분포의 측정이 가능한 레이더 자료를 이용해 결측치를 추정하여 각각의 방법을 비교하였다. 임진강 유역의 15개 지상관측소를 대상으로 교차검정(Cross validation) 분석을 실시해 본 결과, CCWM 방법과 ANN기법에 의한 RMSE가 0.46~1.79의 범위를 보였고, 보정레이더를 이용하여 결측치를 추정한 경우RMSE가 0.05~2.26의 범위를 보여 기존의 전통적 결측치 추정방법보다 실측치에 가까운 결과를 보였다. 이는 레이더자료가 지점 강우자료와는 달리 강우의 시공간적 변동성을 고려한 공간분포의 정보를 지니고 있기 때문인 것으로 판단된다.

• 한국공간정보시스템학회:학술대회논문집
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• 2005.05a
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• pp.237-241
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• 2005

본 연구에서는 한국 남해해역의 해양환경 중 해수표면온도의 변화와 Cochlodinium polykrikoides 적조의 시공간 분포가 밀접한 관련성을 가지고 있음을 파악하였다. GIS와 원격탐사기술은 한국 중남부해역에 적용되었고, 이 지역은 매년 하계에 적조가 최초로 발생하는 지역이다. 해수표면온도를 포함한 적조의 이동 경향을 비교하기 위해 현장조사에 의한 적조 분포가 조사선에 의해 수집되어졌다. 또한, 적조의 위성영상과 해수표면수온 분포를 Landsat 위성자료를 통해 획득하였다. 위성자료에 의해 추정된 적조의 분포와 해수표면온도분포는 유사한 패턴을 나타내고 있음을 알 수 있었다. 여름철에 한반도 남동부 연안해역에서 나타나는 적조의 분포와 이동경향은 이 지역의 해수온도 분포의 시공간적인 분포에 밀접한 관계가 있다.

• Journal of the Korean Association of Geographic Information Studies
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• v.13 no.3
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• pp.14-28
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• 2010

The aim of this study is to investigate crime hotspot areas using the spatio-temporal cluster analysis which is possible to search simultaneously time range as well as space range as an alternative method of existing hotspot analysis only identifying crime occurrence distribution patterns in urban area. As for research method, first, crime data were collected from criminal registers provided by official police authority in M city, Gyeongnam and crime occurrence patterns were drafted on a map by using Geographic Information Systems(GIS). Second, by utilizing Ripley K-function and Space-Time Scan Statistics analysis, the spatio-temporal distribution of crime was examined. The results showed that the risk of crime was significantly clustered at relatively few places and the spatio-temporal clustered areas of crime were different from those predicted by existing spatial hotspot analysis such as kernel density analysis and k-means clustering analysis. Finally, it is expected that the results of this study can be not only utilized as a valuable reference data for establishing urban planning and crime prevention through environmental design(CPTED), but also made available for the allocation of police resources and the improvement of public security services.

• Journal of KIISE:Computing Practices and Letters
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• v.15 no.1
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• pp.57-61
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• 2009

To increase the efficiency of mining process and derive accurate spatio-temporal patterns, continuous values of attributes should be discretized prior to mining process. In this paper, we propose a discretization method which improves the mining efficiency by reducing the data size without losing the correlations in the data. The proposed method first s original trajectories into approximations using line simplification and then groups them into similar clusters. Our experiments show that the proposed approach improves the mining efficiency as well as extracts more intuitive patterns compared to existing discretization methods.

• Journal of the Korean Association of Geographic Information Studies
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• v.10 no.4
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• pp.60-74
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• 2007

For quantitative analysis of spatio-temporal distribution pattern on marine environment, spatial autocorrelation statistics on the both global and local aspects was applied to the observed data obtained from Gwangyang Bay in South Sea of Korea. Global indexes such as Moran's I and General G were used for understanding environmental distribution pattern in the whole study area. LISAs (local indicators of spatial association) such as Moran's I ($I_i$) and $G_i{^*}$ were considered to find similarity between a target feature and its neighborhood features and to detect hot spot and/or cold spot. Additionally, the significance test on clustered patterns by Z-scores was carried out. Statistical results showed variations of spatial patterns quantitatively in the whole year. Then all of general water quality, nutrients, chlorophyll-a and phytoplankton had strong clustered pattern in summer. When global indexes showed strong clustered pattern, the front region with a negative $I_i$ which means a strong spatial variation was observed. Also, when global indexes showed random pattern, hot spot and/or cold spot were/was found in the small local region with a local index $G_i{^*}$. Therefore, global indexes were useful for observing the strength and time series variations of clustered patterns in the whole study area, and local indexes were useful for tracing the location of hot spot and/or cold spot. Quantification of both spatial distribution pattern and clustering characteristics may play an important role to understand marine environment in depth and to find the reasons for spatial pattern.

• Journal of Korean Society for Geospatial Information Science
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• v.24 no.4
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• pp.75-81
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• 2016

This study focused on exploring real transaction price of apartment and spatial and temporal heterogeneity of the variables that influence real transaction price of apartment from the spatial and temporal perspective. As independent variables that are considered to influence real transaction price of apartment, transport, local characteristics, educational conditions, population, and economic characteristics were taken into account. Accordingly, the influence of independent variables and spatial distribution pattern were analyzed from the global and local aspects. The spatial and temporal changing patterns of real transaction price of apartment which is a dependent variable were analyzed. First, to establish an analysis model, OLS analysis and GWR analysis were conducted, and thereby more efficient and proper model was selected. Secondly, to find spatial and temporal heterogeneity of independent variables with the use of the selected GWR model, Local $R^2$ was used for local analysis. Thirdly, to look into spatial distribution of independent variables, kriging analysis was carried out. Therefore, based on the results, it is considered that it is possible to carry out more microscopic housing submarket analysis and lay the foundation for establishing a policy on real property.

• Journal of the Economic Geographical Society of Korea
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• v.20 no.2
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• pp.158-172
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• 2017

This study analyzes the time-space variability for the weekly passenger flow of the Seoul Subway system based on the dynamic visualization methods. For the purpose, we utilize one-week T-card transaction databases. By applying data mining algorithms, we extract passenger data for edge flows, on/off passengers at each subway station per minute interval time. It is practically intractable to analyze such spatio-temporal passenger flows by general statistical techniques. We employ dynamic visualization methods to analyze intuitively and to grasp effectively characteristics of the diurnal passenger flows on the Seoul Metropolitan Subway system during one week. As the result, we found that substantial differences exist on the spatio-temporal distribution patterns among days as well as between weekdays and weekend. We also investigates the time-space variability among eight major centers, and we found wide differences in their spatio-temporal distribution patterns.

• Journal of Korean Society for Geospatial Information Science
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• v.22 no.1
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• pp.63-70
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• 2014

This study is to analyze impact of geography and timing on the real transactions prices of apartment complexes in Seoul using data provided by the Ministry of Land, Infrastructure and Transport. The average real transactions and location data of apartment complex was combined into the GIS data. First, the pattern of apartment real transaction price change by period and by area was analyzed by kriging, the one of the spatial interpolation technique. Second, to analyze the pattern of apartment market price change by administrative district(administrative 'Dong' unit), the average of market price per unit area was calculated and converted to Moran I value, which was used to analyze the clustering level of the real transaction price. Through the analysis, spatial-temporal distribution pattern can be found and the type of change can be forecasted. Therefore, this study can be referred as of the base data research for the housing or local policies. Also, the regional unbalanced apartment price can be presented by analyzing the vertical pattern of the change in the time series and the horizontal pattern of the change based on GIS.

• Journal of the Korean Geographical Society
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• v.47 no.2
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• pp.193-207
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• 2012

This study discussed characteristics of Shindu Coastal Dune as habitat, and relationship between geodiversity and biodiversity. It was identified spatio-temporal variation of incoming nutrients depended on geomorphic differences of foredunes. The main incoming path of nutrients into coastal dune was considered as influx with movement of wind blown sands from the beach and tidal f lat. Concentrations of Na, Mg, K, Ca, and P in blown sands were compared. Concentrations of Na, Mg, and K showed high and irregular pattern in favorable condition of influx of blown sand. So these nutrients were related with geomorphic characteristics of foredunes. However, Na was also influenced by other factor such as salt spray. P was independent from effects of sea water and blown sands. In the case of Ca, a large coastal dune system rather than localized forms of foredunes made differences in the variation. Due to differences in spatio-temporal variation of nutrients, patterns of major vegetation could be inferred to appear differently. This study shows geomorphic dynamics of coastal dunes as habitat, and will provide information for coastal dune management and for understanding biological distribution and growth pattern in coastal dune.