• Journal of the Korean Geographical Society
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• v.33 no.2
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• pp.325-338
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• 1998

본 연구에서는 시.공 복합적인 선형 점 자료를 대상으로 시간과 공간을 함께 고려했을 때 자료 내에 군집(cluster)-시.공 복합 군집(space-time cluster)-이 존재하는 가를 검증하는 방법에 대해 논의하고, 실제 교통사고지점의 분포자료를 분석하여 군집의 유무를 통계적으로 검증하였다. 통계 분석의 결과 다음과 같은 사실이 확인되었다. 첫째, Knox의 분할표 방법과 Mantel의 역수 변환을 이용한 일반화된 회귀분석방법 모두 임계 거리 및 임계 시간 간격의 선택이 분석결과에 영향을 미친다. 둘째, 이러한 임의성을 극복하기 위해 다양한 임계 거리 및 임계 시간 간격(혹은 부가 상수)에 대해 반복 실험한 결과, 일부 임계값의 조합에서 시간과 공간이 서로 독립적이라는 귀무가설을 기각할 수 있는 증거가 발견되었다. 셋째, 시.공 복합 군집의 파악에 가장 적합한 임계 거리와 임계 시간 간격은 공간적으로는 7000m, 시간적으로는 14일 혹은 21일이다. 마지막으로, 통계 분석과정에서 자료에 존재하는 중복 기록 사고들의 존재가 밝혀짐으로써 시.공 복합군집 검증이 탐험적 자료 분석(exploratory data analysis)의 도구로서 가지는 가치를 확인할 수 있었다.

• Journal of the Korean association of regional geographers
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• v.6 no.3
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• pp.169-184
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• 2000

Industrial clusters and their boundaries are identified by factor and hot spot analyses for the greater Cincinnati metropolitan area in USA. While traditional input-output approach identified aspatial industrial clusters, this study combines traditional approach with GIS techniques to identify their boundaries. Combining the results of input-output industrial clusters with the leading industries groups, we have identified five leading industry clusters. They are food (20), chemicals (28), metal manufacturing (32), metal products (33), and machinery (35). We also used hot spot analysis to visualize each industry cluster on the research area by using Arcview software. Determining the degree to which such industries are associated spatially and their spatial delimitation may be an additional approach to measuring the efficiency of the spatial organization of an economy. It is hoped that the industrial clusters and industrial spatial clusters approaches may also proved the basis for the development of new models of the spatial arrangement of industry at a level more aggregated than that of the single plant or firm.

• Journal of the Korean Geographical Society
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• v.39 no.3
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• pp.457-472
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• 2004

The purpose of this study is to analyze spatial patterns of traffic accidents and to investigate spatial relations among neighboring spatial objects by applying GIS and spatial data mining methods. This study investigated traffic accident data in Kangnam-gu, Seoul, as a case study. As a result, four clusters were emerged based on individual attributes of traffic accidents. Each cluster showed distinctive properties. In spatial associations between individual attributes of traffic accidents and neighboring spatial objects, there were many rules according to concept hierarchy and definition of spatial relations. Although all rules were not be interesting and significant, they could be a clue to investigate more.

• Journal of the Korean association of regional geographers
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• v.18 no.4
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• pp.464-472
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• 2012

To assess the space-time clustering of FMD(Foot-and-Mouth Disease) epidemic occurred in Korea between November 2010 to April 2011, geographical information system (GIS)-based spatial analysis technique was used. Farm address and geographic data obtained from a commercial portal site were integrated into GIS software, which we used to map out the color-shading geographic features of the outbreaks through a process called thematic mapping, and to produce a visual representation of the relationship between epidemic course and time throughout the country. FMD cases reported in northern area of Gyounggi province were clustered in space and time within small geographic areas due to the environmental characteristics which livestock population density is high enough to ease transmit FMD virus to the neighboring farm, whereas FMD cases were clustered in space but not in time for southern and eastern area of Gyounggi province. When analyzing the data for 7-day interval, the mean radius of the spatial-time clustering was 25km with minimum 5.4km and maximum 74km. In addition, the radius of clustering was relatively small in the early stage of FMD epidemic, but the size was geographically expanded over the epidemic course. Prior to implementing control measures during the outbreak period, assessment of geographic units potentially affected and identification of risky areas which are subsequently be targeted for specific intervention measures is recommended.

• Fire Science and Engineering
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• v.23 no.1
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• pp.15-20
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• 2009

For the effective management of forest fire, understanding of regional forest fire patterns is needed. In this paper, forest fire ignition and spread characteristics were analyzed based on forest fire statistics. Fire occurrences, burned area, rate of spread, and burned area per fire between 1991 and 2007 were parameterized for the cluster analysis, which results were displayed using GIS to detect spatial patterns of forest fire. Administrative districts such as cities and counties were classified into 5 clusters by fire susceptibility. Metropolitan areas had fire characteristics that were infrequent, slow rate of spread, and small burned area. However, 4 cities and counties showing fast rate of spread, and large burned area, in the eastern regions of Taeback Mountain range, were the most susceptible areas to forest fire. The next vulnerable cities and counties were located in the West and South Coast area.

• The Korean Journal of Applied Statistics
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• v.27 no.4
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• pp.561-575
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• 2014

In this paper, we propose a penalized likelihood method to detect local spatial clusters associated with disease. The key computational algorithm is based on genlasso by Tibshirani and Taylor (2011). The proposed method has two main advantages over Kulldorff's method which is popoular to detect local spatial clusters. First, it is not needed to specify a proper cluster size a priori. Second, any type of covariate can be incorporated and, it is possible to find local spatial clusters adjusted for some demographic variables. We illustrate our proposed method using tuberculosis data from Seoul.

• Proceedings of the Korean Society of Disaster Information Conference
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• 2016.11a
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• pp.261-262
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• 2016

교통사고의 발생요인에는 다양한 원인들이 있지만 본 연구에서는 공간적으로 접근하여 사고유형별 분포특성을 도출하기 위해 공간적 자기상관성 분석을 수행하였다. 논문에서는 2012년부터 2014년까지 울산광역시에서 발생된 교통사고를 대상으로 분석을 수행하였다. 그 결과 울산시 전체 교통사고 약 53%는 안전운전불이행이며 다음으로는 안전거리미확보, 신호위반 순으로 나타났다. 밀도분석 결과는 사고유형별로 분포가 차이가 있었으며 안전운전불이행의 경우 가장 큰 군집은 중심시가지인 달동과 삼산동 중심에 나타났으며 중앙선침범은 도시의 중심부 보다는 면지역에 넓게 퍼져서 발생되었으며 산업단지가 있는 동구지역에 군집이 크게 나타났다. 따라서 읍면동별 공간적 특성을 파악하기 위해 Moran's I분석과 LISA분석을 수행한 결과 안전운전불이행, 안전거리미확보, 신호위반, 교차로운행방해 모두 중심시가지인 신정동, 달동, 삼산동이 공간적 자기상관성이 높았으며 중앙선침범의 경우 밀도분석 결과와 마찬가지로 중심시가지 이외에 읍면 지역도 자기상관성이 더 높게 나타났다. 이를 통해 사고유형별 공간의존성 및 이질성을 파악하여 교통사고 다발지역을 도출하고 이를 토대로 지역특성에 맞는 저감 대책 마련에 활용되고자 한다.

• Proceedings of the Korean Society of Computer Information Conference
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• 2019.07a
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• pp.315-316
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• 2019

전투복, 군용 천막 등에 사용되는 위장무늬는 군 작전 수행 시 주변 환경의 색상, 패턴을 모사하여 개인병사 및 무기체계의 위장 기능을 극대화하고, 이를 통해 아군의 생명과 시설피해를 최소화하기 위한 목적으로 사용된다. 특히 최근 들어 군의 작전환경과 임무가 복잡하고 다양해짐에 따라, 작전환경에 대한 데이터의 취득 및 정량적 분석을 통해 전장 환경에 최적화된 위장무늬 패턴 및 색상 추출에 대한 연구의 필요성이 증대되고 있다. 본 논문에서는 한반도 자연환경 영상에 대한 자기 조직화 지도(SOM, Self-organizing Map) 기반의 한반도 자연환경 대표 색상 군집화 연구 방법에 대해 서술한다. 이를 위해 한반도 내 위도를 고려한 장소에서 시간별, 계절별 자연환경 영상 수집을 진행하며, 수집된 영상 내 다수의 화소의 군집화를 위해 2차원 SOM을 활용한다. 영상 내 각 화소의 색상 값에 대한 SOM의 학습 시, RGB공간상의 색차/색상 인지 왜곡을 피하기 위하여 CIEDE2000 색차 식을 통해 군집화를 진행한다. 실험결과에서는 온라인상으로 수집한 여름 및 가을철 대표 색상 군집화 결과와, 현재까지 수집된 계절별 자연환경 사진 내 6억 7648개 화소에 대한 대표 색상 군집화 결과를 보여준다.

• Journal of the Korean Association of Geographic Information Studies
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• v.18 no.3
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• pp.89-101
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• 2015

Outbreaks of highly pathogenic avian influenza(HPAI) subtype H5N8 have occurred in Korea, January 2014 and it continued more than a year until 2015. And more than 5 million heads of poultry hads been damaged in 196 farms until May 2014. So, we studied the spatial, temporal and spatio-temporal patterns of the HPAI epidemics for understanding the propagation and diffusion characteristics of the 2014 HPAI. The results are expressed using GIS. Throughout the study period three epidemic waves occurred over the time. And outbreaks made three clusters in space. First spatial cluster is adjacent areas of province of Chungcheongbuk-do, Chungcheongnam-do and Gyeonggi -do. Second is Jeonlabuk-do Gomso Bay area. And the last is Naju and Yeongam in Jeollanam-do. Also, most of spatio-temporal clusters were formed in spatially high clustered areas. Especially, in Gomso Bay area space density and spatio-temporal density were concurrent. It means that the effective prevention activity for HPAI was carried out. But there are some exceptional areas such as Chungcheongbuk-do, Chungcheongnam-do, Gyeonggi-do adjacent area. In these areas the outbreak density was high in space but the spatio-temporal cluster was not formed. It means that the HPAI virus was continuing inflow over a long period.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.14 no.2
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• pp.39-53
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• 2015

The paper analyzes factors to affect pedestrian volumes by land-use type using 2012 Seoul Pedestrian Survey. First of all, five groups were classified based on land-use types around survey points such as residential, commercial, industrial and green uses, using k-average cluster analysis. Then, differences in average pedestrian volumes by group were compared for a day and time of day. In addition, multiple regression analysis was employed to identify factors to affect pedestrian volumes, considering physical features, land use types, public transportation accessibility, and socio-economic indices as independent variables by spatial hierarchy. Model results show that the walkway width positively influenced on pedestrian volumes for all groups, whereas other variables differently affected by group. Our results can be used as basic data for establishing polices with respect to pedestrian road design and improvement as well as estimating pedestrian demand by land-use type.