• Journal of Cadastre & Land InformatiX
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• v.46 no.1
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• pp.75-86
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• 2016

This study examines the social issues between the central and local governments related with the underground space after happenings of sinkholes in Jamsil area in July, 2014. In this study, we consider the keyword network of the social network analysis as a research methodology. The social issues regarding the underground space have been dealt with through the analysis of the centrality and group density to know the attributes of the network. The results show that the government has been steadily helpful to the local governments for establishing the socialized law for the underground space. This research suggests that the laws and technologies as to the underground space issues cooperate each other in the future. It also shows that the government should enact the policies and the national plans for the development of the underground.

• Journal of the Korean Association of Geographic Information Studies
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• v.11 no.4
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• pp.122-138
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• 2008

A pixel-based approach to urban quality of life assessment can be regarded as a spatial decision problem under the condition of complexity because it searches the urban space for evidence of hot spots of quality of life based on multiple and differentially weighted evaluation criteria. Such an assessment involves inappropriate scaling of several incommensurate criteria, much unstructured subjectivity in the decision maker's judgment, and the large data handling in a raster GIS environment. There is a need for identifying alternative approaches to tackle the ill-structured problem in urban quality of life assessment. In this context, this research proposes and implements a spatial multicriteria analysis approach to evaluate urban quality of life in a raster GIS environment. The implementation of this methodology is illustrated with a case study of the Atlanta metropolitan area. Results indicate that the proposed methodology may provide an alternative approach for evaluating the quality of life in an urban environment.

• Journal of the Korean Geographical Society
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• v.34 no.5
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• pp.473-491
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• 1999

세균성 이질은 국내 제1종 법정 전염병으로 분류되어 관리되고 있는 질환으로서 1998년 이후 그 발병 사례가 급속히 증가하고 있다. 본 연구는 1999년 3월 부산시 사상구에서 집단 발병한 세균성 이질을 대상으로 하여, 각 환자들의 발병 시점과 장소의 분포패턴에 대한 지리학적 고찰을 목적으로 한다. 환자분포의 특징적 공간패턴과 그들의 시계열적 확산 양상 등을 탐색하기 위한 방법론은 보건지리학과 지도학 및 공간통계학에 기반을 둔 공간분석기법을 중심으로 설정하였다. 분석자료는 해당 지역의 수치지형도, 지적도, 인구 센서스 자료를 포함한 GIS 데이터베이스로 구축되었다. 인구분포를 감안한 밀도구분도를 바탕으로 개별환자의 위치자료와 동 단위로 집계된 자료를 자료의 형태에 따라 분석기법을 달리하였으며, 환자 발생 밀도, 상대적 위험지수 등을 지도화하여 역학자료의 시각적 통계적 분석을 수행하였다. 환자분포의 공간적 중심위치와 분산의 변화 등 기술적 통계분석과 함께 제1차 공간속성을 커널추정법으로 찾아보았다. 이와 더불어 ‘공간적 의존성’과 관련된 제2차 공간속성은 K-함수와 시뮬레이션을 통해 분석하여 군집성 등이 통계적으로 확인되었다. 본 연구를 통해 역학조사시 GIS의 활용사례가 제시되었으며, 모집단 인구를 고려한 확률지도 작성 기법과 다양한 데이터 가시화 방법, 그리고 시계열별 발생 환자들의 지리적 변이를 분석 하는데 따르는 문제들이 논의되었다.

• Journal of The Geomorphological Association of Korea
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• v.20 no.4
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• pp.85-99
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• 2013

The objective of this paper is to analyze the spatial distribution of errors in the DEM generated using waterlines from multi-temporal remote sensing data and to assess flood vulnerability. Unlike conventional research in which only global statistics of errors have been generated, this paper tries to quantitatively analyze the spatial distribution of errors from a probabilistic viewpoint using geostatistical simulation. The initial DEM in Baramarae tidal flats was generated by corrected tidal level values and waterlines extracted from multi-temporal Landsat data in 2010s. When compared with the ground measurement height data, overall the waterline-based DEM underestimated the actual heights and local variations of the errors were observed. By applying sequential Gaussian simulation based on spatial autocorrelation of DEM errors, multiple alternative error distributions were generated. After correcting errors in the initial DEM with simulated error distributions, probabilities for flood vulnerability were estimated under the sea level rise scenarios of IPCC SERS. The error analysis methodology based on geostatistical simulation could model both uncertainties of the error assessment and error propagation problems in a probabilistic framework. Therefore, it is expected that the error analysis methodology applied in this paper will be effectively used for the probabilistic assessment of errors included in various thematic maps as well as the error assessment of waterline-based DEMs in tidal flats.

• The Korean Journal of Applied Statistics
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• v.35 no.5
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• pp.657-666
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• 2022

An informative predictor subspace is useful to estimate the central subspace, when conditions required in usual suffcient dimension reduction methods fail. Recently, for multivariate regression, Ko and Yoo (2022) newly defined a projective-resampling informative predictor subspace, instead of the informative predictor subspace, by the adopting projective-resampling method (Li et al. 2008). The new space is contained in the informative predictor subspace but contains the central subspace. In this paper, a method directly to estimate the informative predictor subspace is proposed, and it is compapred with the method by Ko and Yoo (2022) through theoretical aspects and numerical studies. The numerical studies confirm that the Ko-Yoo method is better in the estimation of the central subspace than the proposed method and is more efficient in sense that the former has less variation in the estimation.

• Proceedings of the Korean Association of Geographic Inforamtion Studies Conference
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• 2007.10a
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• pp.131-139
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• 2007

국토기본법과 국토의 계획 및 이용에 관한 법률은 국토의 지속 가능한 발전을 위한 정책 및 계획을 규정하고 있다. 이를 효율적으로 달성하기 위한 수단으로GIS를 기반으로 공간의사결정 지원체계 구축에 대한 수요가 높아지고 있다. 이는 그 동안 행정업무를 위한 자료관리 중심의 정보화에서 공간자료분석을 기반으로 한 정보화에 대한 새로운 수요라고 할 수도 있다. 그러나 국토공간계획을 지원하기 위한 의사결정지원체계를 성공적으로 구축하기 위해 해결해야 할 많은 과제들이 있다. 본 연구는 국토공간계획을 위한 의사결정지원체계를 구축하는데 장애가 되는 과제를 파악하고, 해결방향을 제시하는데 목적을 두고 있다. 이를 위해 전문가를 대상으로 한 델파이 조사를 실시했다. 본 연구는 공간의사결정지원체계의 설계 및 개발에 영향을 미치는 주요 요인을 중심으로 research questions를 가지고 접근했다. 시스템 설계 관점에서 처리결과에 영향을 미치는 요인으로 입력되는 자료와 지식, 분석처리하는 방법, 인터페이스 등을 중심으로 research question을 설정했다. 시스템 개발과 관련하여 개발도구 확보, 이해관계자 참여 방안, 시스템의 지속성 확보 등을 중심으로 research questions를 설정했다. 마지막은 향후 공간의사결정 지원체계의 연구 및 개발을 효율적으로 수행하기 위한 파트너쉽에 대한 research question이다. 지금까지 국내에서 공간의사결정지원체계 구축과 관련해 기초적인 이론이나 방법론에 대한 연구가 미흡했다. 대부분 외국의 연구 및 개발사례를 소개하는 수준에 불과하다. 특히 공간의사결정지원체계를 구축하거나 운용하는 기반기술인 개발도구에 대한 기술수준이 상당히 미흡하다. 조사결과에서 공개소프트웨어 도입에 대한 필요성 강조가 이를 반증하고 있다. 또한 시민사회의 성숙, 다양한 사회단체 출현 등으로 국토공간계획 과정에 이해관계자 참여정도가 질적 양적으로 높아질 것으로 예상된다. 그러나 이에 대응하기 위한 기술, 기법 등에 대한 연구는 매우 미흡하고 단편적으로 관련 기술을 소개하는 정도이다. 국토공간계획 및 정책과 관련한 다양한 문제해결을 위한 공간의사결정지원체계를 구축하기 위해서 장기간에 걸긴 단계적 접근이 필요하다. 국토공간계획은 우리나라만의 자연 환경 및 인문환경의 특성이 반영되어야 할 것이다. 이를 위해 우리의 개발방법론, 우리의 기술이 개발되어야 하며, 이를 체계적으로 구현할 수 있는 협력체계 구축이 필요하다.

• Land and Housing Review
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• v.12 no.4
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• pp.81-92
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• 2021

This study investigates whether urban expansion can act as a cause of the decline of the original city center through the Space Syntax methodology. The urban spatial structure analysis was conducted targeting the downtown area of Jeju-eupseong. The time points for longitudinal analysis were set at five points between 1914 and 2021 including the Japanese colonial period when the cadastral map was drawn up in Jeju City, and the urban spatial structure was analyzed and compared for each time point. ASA (Angular Segment Analysis) was used as a technique for urban spatial structure analysis. This study shows that urban expansion is a cause of the decline of the original downtown. The original city center has moved away from the center as the urban structural change due to the urban expansion. The urban structure of the eastern part of Jeju City has undergone a major transformation between 1914 and 2021. As the old Jeju area where the original city center was located is geographically in contact with the sea, urban sprawl has been made toward Halla Mountain and further to the south of Jeju. Accordingly, the city center has transformed from a monocentric to a polycentric structure. Due to the dynamics of the urban sprawl, the old downtown of Jeju became one of the peripheral neighbourhoods in the Greater Metropolitan of Jeju.

• Journal of the Korean Geographical Society
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• v.46 no.3
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• pp.366-381
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• 2011

A competitive location problem in discrete space is computationally difficult to solve in general because of its combinatorial feature. In this paper, we address an alternative method for solving competitive location problems in discrete space, particularly employing deterministic allocation. The key point of the suggested method is to reducing the number of predefined potential facility sites associated with the size of problem by utilizing geometric concepts. The suggested method was applied to the existing broadband marketplace with increasing competition as an application. Specifically, we compared computational results and spatial configurations of two different sized problems: the problem with the original potential sites over the study area and the problem with the reduced potential sites extracted by a GIS-based geometric algorithm. The results show that the competitive location model with the reduced potential sites can be solved more efficiently, while both problems presented the same optimal locations maximizing customer capture.

• Korean Journal of Environment and Ecology
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• v.36 no.2
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• pp.202-216
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• 2022

Animals exhibit certain behaviors and movement patterns as they react to their internal needs, external stimuli, and surrounding environments. They have a bounded range in which they mostly spend their time, and it is referred to as a home range. Based on the fact that the home range is a critical area for the survival and preservation of species, there has been a growing body of research on developing more precise home range estimation methods to use the estimated ranges as a ground for establishing an effective conservation policy since the early 1940s. Recent rapid advancements in telemetry technology that resulted in the presence of autocorrelation between locations with short time intervals revealed the limitations of the existing estimators. Many novel estimators have been developed to compensate for it by incorporating autocorrelation in calculating home ranges. However, studies on the animal home range are still in their early stage in Korea, and newly developed methodologies have not yet been adopted. Therefore, this study aims to introduce the foreign home range estimation methods and foster domestic research activities on home ranges. Firstly, we compared and contemplated seven estimators by categorizing them into geometrical and statistical methodologies and then divided them into estimators that assume independent observations and those that consider autocorrelation in each category. After that, the home ranges of black-tailed gulls (Larus crassirostris) were calculated using GPS tracking data for the month of June and derived home range estimators by applying the methodology introduced in this study. We analyzed and compared the results to discuss the strengths and weaknesses of each method. Lastly, we proposed a guideline that can help researchers choose an appropriate estimator for home range calculation based on the animal location data characteristics and analysis purpose.

• Journal of the Korea Society for Simulation
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• v.21 no.4
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• pp.35-46
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• 2012

As complexity of real-time systems is being increased ad hoc approaches to analysis of such systems would have limitations in completeness and coverability for states space search. Formal means using a model-based approach would solve such limitations. This paper proposes a model-based formal method for logical analysis, such as safety and liveness, of real-time systems at a discrete event system level. A discrete event model for real-time systems to be analyzed is specified by DEVS(Discrete Event Systems Specification) formalism, which specifies a discrete event system in hierarchical, modular manner. Analysis of such DEVS models is performed by Communicating DEVS (C-DEVS) formalism of a timed global state transition specification and an associated analysis algorithm. The C-DEVS formalism and an associated analysis algorithm guarantees that all possible states for a given system are visited in an analysis phase. A case study of a safety analysis for a rail road crossing system illustrates the effectiveness of the proposed method of the model-based approach.