• 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.

• Journal of the Korean association of regional geographers
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• v.10 no.2
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• pp.356-370
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• 2004

New communication and information technologies such as the Internet are space-adjusting technologies. The Internet changes the spatial proximity by improving the connections between people and organizations separated by geographical distance This paper examines the digital position of individual nation-states on a global cyberspace. The number of inter-domain hyperlinks embedded in websites for 47 nations was gathered using the AltaVista in 2001 Data were also obtained on the geographical distance among the nations. The results indicate that the u.s. is the most central nation on the global cyberspace, followed by the U.K., Germany, Australia, Canada, Italy, France, China and Japan. The most peripheral nations are Uruguay, Luxemburg, and UAE. It also examines the relationship between the digital positions of 47 nations and their physical locations. The results indicate that digital structure on the cyberspace is not significantly related to geographical distance among those nations.

• Journal of Environmental Impact Assessment
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• v.29 no.4
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• pp.298-306
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• 2020

This study was conducted to examine the impact of the correlation between habitat suitability of the Saemangeum lake area for otters and spatial variables (watersides, wetlands, farmlands, urban areas, roads, etc.) on the inhabitation of otters. As a result of the habitat suitability analysis, it was found that 380grids of 1097 grids (34.6%) studied are most suitable and suitable, whereas 413 grids of 1097 grids (37.7%) of the total are marginal and unsuitable. Comparatively analyzing otter traces data against for each spatial variable in the Saemangeum area revealed that the distance to the road or man-made areas is directly proportional to the number of otter traces, while more traces of otters were found areas close to waters. Despite the impact from the internal construction of Saemangeum lake, there found 2 to 6 times more otter traces in the area farthest from the urban areas and roads compared to the area nearest to the urban areas and roads. Thus, when restoring habitats for otters, a minimum of 500(m) distance to roads or urban areas, which can be considered as a threat to the habitats, must be secured.

• Spatial Information Research
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• v.18 no.4
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• pp.99-108
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• 2010

Space Syntax methodology can be quantitatively calculated spatial cognitive analysis by number of turns_ In the existing GIS-based spatial information service provide 'physical distance' due to the shortest distance as a priority. but pedestrians tends to choose the path with concerned a lot of emphasis of safety, more vitality way from the crime at night, traffic accidents, and comfort on a road. Human's 'psychological distance' may reflect the spatial information services and provided path should be. In this study, using GIS Road Data implements the axial map with idea of the linear simplification principles. Traditional axial map of the Space Syntax get the assumption from the actual traffic values by comparing the results of correlation relationship. Through these methods, the actual relationship between traffic and test values have the correlation value($R^2$= 0.5387) 50% level and was able to get the results.

• Korean Journal of Cognitive Science
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• v.14 no.1
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• pp.17-28
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• 2003

In order to provide natural images with a specified depth through three-dimensional display system, the stereo images should be similar to those projected from real environment as much as possible. Even when two persons see an identical scene, the binocular Parallax between two images of an object varies as a function of one's inter-pupilary distance (IPD). In this study, we investigated whether individual differences, such as IPD and accommodative vergence, would affect the perception of three dimensional scene provided by stereo-images. Results showed that a person's IPD is correlated with the limit of screen and binocular parallax for single vision, and affects the perceived depth of an object on fixation. More specifically, with longer IPD the limit of screen and binocular parallax for single vision is decreased, and the perceived depth is reduced. These results suggest that the screen and binocular parallax of an object should be calibrated with regard to users IPD to provide natural stereo-images with a specified depth and to Prevent double vision.

• Journal of Korean Tunnelling and Underground Space Association
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• v.11 no.2
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• pp.199-211
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• 2009

Development of underground space is actively performed globally for better life in the surface, and the scale of the space is increasing. Extreme care should be taken in the construction of the underground space in urban areas in order to avoid damage of adjacent structures and interference with existing underground space. In case of shallow tunnels, reinforcement of ground and structures is necessary to minimize the damage to structures due to excavation but any standard for optimum range of the reinforcement has not been established yet. In this paper, a series of numerical analyses have been performed for a 20 m diameter tunnel excavated underneath a structure to investigate the degree of damage of the structure according to vertical and horizontal spacing between the tunnel and structure. In addition to that, optimum range of reinforcement is presented for each case where reinforcement is required. It has been observed that the reinforcement is necessary for the ground condition adapted in the analyses as follows: (1) if horizontal spacing ($S_{H}$) approaches to 0D (D: equivalent diameter of tunnel) for vertical spacing (Sv) of 0.5D, and (2) if tunnel exists underneath the structure for vertical spacing (Sv) of 0.75D. The reinforcement is not necessary for Sv of 10 regardless of $S_{H}$. It also has been obtained that the optimum ranges of the reinforcement around structure foundation are 7 m in depth and whole width of the structure and 5 m beyond tunnel sidewall. These reinforcememt ranges have been confirmed to be enough for stability of the structure if types of reinforcement method is appropriately selected.

• Journal of the Economic Geographical Society of Korea
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• v.11 no.3
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• pp.492-507
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• 2008

Many classical network analysis methods approach networks in aspatial perspectives. Measuring network reliability and finding critical nodes in particular, the analyses consider only network connection topology ignoring spatial components in the network such as node attributes and edge distances. Using local network autocorrelation measure, this study handles the problem. By quantifying similarity or clustering of individual objects' attributes in space, local autocorrelation measures can indicate significance of individual nodes in a network. As an application, this study analyzed internet backbone networks in the United States using both classical disjoint product method and Getis-Ord local G statistics. In the process, two variables (population size and reliability) were applied as node attributes. The results showed that local network autocorrelation measures could provide local clusters of critical nodes enabling more empirical and realistic analysis particularly when research interests were local network ranges or impacts.

• Journal of Korean Society for Geospatial Information Science
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• v.4 no.2 s.8
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• pp.79-90
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• 1996

It is well known that point positioning using a C/A-code receiver is severely biased by errors in pseudorange. This paper shows the procedures of quantitive analysis for several error elements and that some methods to monitor SA(selective availability) of witch process is not opened are proposed. It is possible to verify the effects of SA in the Doppler shift and receiver clock drift variation. Easy methods to reduce SA effects are to fit second order polynomials for the one and a linear function for the other. With periodic autocorrelation functions. SA effects are analyzed and first order Gauss-Markov process parameters are decided.

• Economic and Environmental Geology
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• v.37 no.6 s.169
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• pp.647-655
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• 2004

To identify the influential factors and their relative significance on spatial distribution of $NO_3-N$ in urban ground water, spatial analysis was conducted using GIS and statistical approaches in the Seongnae-Koduk watersheds, where rapid urbanization has been proceeded. Several factors were considered including land-use type, distance to sewage lines, the ratio of impervious surface, and the ratio of green area. The spatial distribution of $NO_3-N$ in the land-use types shows differences between urban and crop field possibly due to the sewage networks in urban areas and the agrochemical uses in crop field. Nitrate concentrations in ground water were decreased with the distance to sewage lines to approximately 60-75 m. Concentrations of nitrate and distances to sewage lines showed negative correlation, indicating that the nitrate contamination was induced from the sewage system and specially significant in urban areas. The negative correlation of the ratio of impervious surface to the nitrate concentration in urban areas also suggested that the source materials of nitrate are introduced from the surface. Consequently, in areas of urbanization processes, systematic management of past-and-present land-use types and sewage systems are the most significant factors in preventing ground water from nitrate contamination.

• Proceedings of the KSRS Conference
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• 2007.03a
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• pp.224-227
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• 2007

마이크로파 센서 자료를 이용하여 태풍 강도를 산출하고자 TRMM TMI로부터 관측된 자료와 태풍 강도의 최대 상관성을 나타내는 지역올 찾고 최적의 상관 변수를 선정하였다. 분석기간은 2004년 6월부터 9월까지 발생된 태풍으로써 18개의 사례이다. TMI로부터 관측된 85 GHz 채널의 밝기온도，구름내 총 수증기량，얼음양，강우 강도，잠열방출양이 태풍 강도와의 상관성 분석을 위한 변수로 분석되었다. 태풍의 강도는 RSMC-Tokyo에서 발표된 Best track의 최대 풍속 자료를 이용하였다. 위성 관측 변수를 태풍 중심으로부터 공간 평균하였을 때 반경 2.0-2.5도 정도의 평균거리에서 최대의 상관성을 보였다. 위성 자료로부터 태풍 중심 풍속을 추정하기 위하여 회귀분석을 하였다. Best track과의 오차는 85 GHz 밝기온도와 수증기량을 이용한 다중 회귀 분석에서 오차가 최소를 보였다. 한편， 태풍강도 예측을 위한 통계모델에 마이크로파 위성 자료를 예측인자로 입력하여 태풍강도의 정확도가 3-6%정도 향상됨을 보였다.