• 제목/요약/키워드: Spatial Statistical Analysis

검색결과 578건 처리시간 0.026초

Modeling pediatric tumor risks in Florida with conditional autoregressive structures and identifying hot-spots

  • Kim, Bit;Lim, Chae Young
    • Journal of the Korean Data and Information Science Society
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    • 제27권5호
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    • pp.1225-1239
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    • 2016
  • We investigate pediatric tumor incidence data collected by the Florida Association for Pediatric Tumor program using various models commonly used in disease mapping analysis. Particularly, we consider Poisson normal models with various conditional autoregressive structure for spatial dependence, a zero-in ated component to capture excess zero counts and a spatio-temporal model to capture spatial and temporal dependence, together. We found that intrinsic conditional autoregressive model provides the smallest Deviance Information Criterion (DIC) among the models when only spatial dependence is considered. On the other hand, adding an autoregressive structure over time decreases DIC over the model without time dependence component. We adopt weighted ranks squared error loss to identify high risk regions which provides similar results with other researchers who have worked on the same data set (e.g. Zhang et al., 2014; Wang and Rodriguez, 2014). Our results, thus, provide additional statistical support on those identied high risk regions discovered by the other researchers.

지진으로 인한 사면변위 해석 시 지반성질 모델의 중요성 (The Importance of Geotechnical Variability in the Analysis of Earthquake-induced Slope Deformations)

  • Kim, Jin-Man
    • 한국지반공학회논문집
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    • 제19권2호
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    • pp.123-133
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    • 2003
  • 사면안정 신뢰성 해석을 통해 다양한 불확실성을 체계적으로 모델링할 수 있는 실용적 인 확률통계 기법을 제시한다. 새로운 제안식은, 지반성질의 확률적 특성화를 위해 공간적 변화와 공간평균으로 인한 분산감소뿐만 아니라 통계 및 측정오차까지도 고려하였다. 지진하중의 불확실성은 인공지진파를 대량으로 생성하고 이를 응답해석에 이용함으로써 반영하였다. 예제 해석결과, 한반도와 같이 지진이 활발하지 않은 지역(중약진 지진대)에서는 일반적 수준의지반성질 변화특성화가 지진위험도 특성화만큼이나 사면 파괴 위험도와 과도한 사면변형 계산값에 영향을 준다는 결론에 도달하였다.

Research on Improving Memory of VR Game based on Visual Thinking

  • Lu, Kai;Cho, Dong Min;Zou, Jia Xing
    • 한국멀티미디어학회논문지
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    • 제25권5호
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    • pp.730-738
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    • 2022
  • Based on visual Thinking theory, VR(virtual reality) game changes the traditional form of memory and maps the content into game elements to realize the immersive spatial memory mode. This paper analyzes the influencing factors of game design and system function construction. This paper proposes a hypothesis: with the help of visual thinking theory, VR game is helpful to improve learners' visual memory, and carries out research. The experiment sets different levels of game through empirical research and case analysis of memory flip game. For example, when judging two random cards. If the pictures are the same, it will be judged as the correct combination; if they are different, the two cards will be restored to the original state. The results are analyzed by descriptive statistical analysis and AMOS data analysis. The results show that game content using the concept of "Memory Palace", which can improve the accuracy of memory. We conclude that the use of spatial localization characteristics in flip games combining visual thinking can improve users' memory by helping users memorize and organize information in a Virtual environment, which means VR games have strong feasibility and effectiveness in improving memory.

공간해상도에 따른 배수경로길이 및 특성유속의 변화 (Changes of Drainage Paths Length and Characteristic Velocities in Accordance with Spatial Resolutions)

  • 최용준;김주철
    • 대한공간정보학회지
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    • 제19권3호
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    • pp.107-114
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    • 2011
  • 본 연구에서는 격자 형태의 지형학적 분산 개념을 이용한 유출해석 시 적절한 격자 해상도 선정을 위해 배수경로 길이의 통계학적 특성과 유역의 동수역학적 매개변수의 변화 양상을 살펴보았다. 배수경로 길이는 지리정보체계의 8방향 흐름방향 알고리즘을 이용하여 산정하였으며, 이로부터 유역의 동수역학적 매개변수를 산정하였다. 분석을 위해 사용된 지형도는 보편적으로 널리 사용되고 있는 1:5,000과 1:25,000 축적을 이용하였으며 각각 5, 10, 15, 20 m와 20, 30, 50, 100, 150, 200 m의 격자 크기를 적용하였다. 분석결과 하천망의 규모에 따라 격자 해상도별 배수 경로 길이의 통계적 특성이 변화함을 볼 수 있었으며, 이로 인해 유역의 동수역학적 매개변수 역시 변화함을 볼 수 있었다. 이러한 변화양상들을 종합적으로 판단하여 볼 때 격자 형태의 지형학적 분산 개념을 이용하여 유출해석을 수행할 경우 1:5,000 지형도의 경우 하천망이 발달된 유역은 격자 해상도 5m, 하천망의 발달이 적은 지역의 경우에는 5~20m의 격자 해상도에서 유역의 지형학적 특성과 동수역학적 특성을 적절히 표현하는 것으로 나타났으며, 1:25,000 지형도는 두 경우 모두 50 m 이하에서 이상의 특성들을 비교적 적절히 표현하는 것으로 나타났다.

공간적 연관구조를 고려한 총범죄 자료 분석 (Analysis of Total Crime Count Data Based on Spatial Association Structure)

  • 최정순;박만식;원유복;김학열;허태영
    • 응용통계연구
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    • 제23권2호
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    • pp.335-344
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    • 2010
  • 공간자료분석에서 공간적 상관성을 배제한 일반적인 회귀모형을 통한 모수 추정값들은 신뢰성의 문제가 지적 되어 오고 있다. 본 연구에서는 공간자료의 상관성을 고려한 모형을 구축하기 위하여 일변량 조건부자기회귀모형을 이용하였으며 베이지안 기법을 통하여 모수를 추정하고 공간상관성이 고려된 공간 가산자료모형과 고려되지 않은 일반 가산자료모형을 비교하였다. 연구 대상으로는 서울시의 25개 행정자치구별 총범죄 자료를 이용하였으며 자료분석을 통하여 도시계획과 같은 국가 정책의 수립에 참고자료로 활용될 수 있으리라 판단된다.

다변량통계분석 및 유역환경모델을 이용한 금호강 중·상류 유역의 수질특성평가 (Assessment of Water Quality Characteristics in the Middle and Upper Watershed of the Geumho River Using Multivariate Statistical Analysis and Watershed Environmental Model)

  • 서영민;권구호;최윤영;이병준
    • 한국물환경학회지
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    • 제37권6호
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    • pp.520-530
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    • 2021
  • Multivariate statistical analysis and an environmental hydrological model were applied for investigating the causes of water pollution and providing best management practices for water quality improvement in urban and agricultural watersheds. Principal component analysis (PCA) and cluster analysis (CA) for water quality time series data show that chemical oxygen demand (COD), total organic carbon (TOC), suspended solids (SS) and total phosphorus (T-P) are classified as non-point source pollutants that are highly correlated with river discharge. Total nitrogen (T-N), which has no correlation with river discharge and inverse relationship with water temperature, behaves like a point source with slow and consistent release. Biochemical oxygen demand (BOD) shows intermediate characteristics between point and non-point source pollutants. The results of the PCA and CA for the spatial water quality data indicate that the cluster 1 of the watersheds was characterized as upstream watersheds with good water quality and high proportion of forest. The cluster 3 shows however indicates the most polluted watersheds with substantial discharge of BOD and nutrients from urban sewage, agricultural and industrial activities. The cluster 2 shows intermediate characteristics between the clusters 1 and 3. The results of hydrological simulation program-Fortran (HSPF) model simulation indicated that the seasonal patterns of BOD, T-N and T-P are affected substantially by agricultural and livestock farming activities, untreated wastewater, and environmental flow. The spatial analysis on the model results indicates that the highly-populated watersheds are the prior contributors to the water quality degradation of the river.

SFR 기법을 이용한 영상 융합의 정확도 향상에 관한 연구 (A Study on the Improvement of Image Fusion Accuracy Using Smoothing Filter-based Replacement Method)

  • 윤공현;손홍규
    • 한국측량학회:학술대회논문집
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    • 한국측량학회 2006년도 춘계학술발표회 논문집
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    • pp.187-192
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    • 2006
  • Image fusion techniques are widely used to integrate a lower spatial resolution multispectral image with a higher spatial resolution panchromatic image. However, the existing techniques either cannot avoid distorting the image spectral properties or involve complicated and time-consuming decomposition and reconstruction processing in the case of wavelet transform-based fusion. In this study a simple spectral preserve fusion technique: the Smoothing Filter-based Replacement(SFR) is proposed based on a simplified solar radiation and land surface reflection model. By using a ratio between a higher resolution image and its low pass filtered (with a smoothing filter) image, spatial details can be injected to a co-registered lower resolution multispectral image minimizing its spectral properties and contrast. The technique can be applied to improve spatial resolution for either colour composites or individual bands. The fidelity to spectral property and the spatial quality of SFM are convincingly demonstrated by an image fusion experiment using IKONOS panchromatic and multispectral images. The visual evaluation and statistical analysis compared with other image fusion techniques confirmed that SFR is a better fusion technique for preserving spectral information.

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Spatial Point-pattern Analysis of a Population of Lodgepole Pine

  • Chhin, Sophan;Huang, Shongming
    • Journal of Forest and Environmental Science
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    • 제34권6호
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    • pp.419-428
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    • 2018
  • Spatial point-patterns analyses were conducted to provide insight into the ecological process behind competition and mortality in two lodgepole pine (Pinus contorta Dougl. ex Loud. var. latifolia Engelm.) stands, one in the Lower Foothills, and the other in the Upper Foothills natural subregions in the boreal forest of Alberta, Canada. Spatial statistical tests were applied to live and dead trees and included Clark-Evans nearest neighbor statistic (R), nearest neighbor distribution function (G(r)), and a variant of Ripley's K function (L(r)). In both lodgepole pine plots, the results indicated that there was significant regularity in the spatial point-pattern of the surviving trees which indicates that competition has been a key driver of mortality and forest dynamics in these plots. Dead trees generally showed a clumping pattern in higher density patches. There were also significant bivariate relationships between live and dead trees, but the relationships differed by natural subregion. In the Lower Foothills plot there was significant attraction between live and dead tees which suggests mainly one-sided competition for light. In contrast, in the Upper Foothills plot, there was significant repulsion between live and dead trees which suggests two-sided competition for soil nutrients and soil moisture.

농촌마을 재생을 위한 정자쉼터 공간구조분석과 이용 후 평가 - 경산권, 김천권 정자쉼터를 대상으로 - (Spatial Structure Analysis and Post Occupancy Evaluation of Jungja(Pavilion) Shelter for Rural Village Regeneration - On the Jungja Shelter in Gimcheom city and Kyeongsan city -)

  • 구민아;엄붕훈
    • 농촌계획
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    • 제23권4호
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    • pp.99-110
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    • 2017
  • This study is to analyze the spatial structure and POE of Jungja(pavilion) shelter for rural village regeneration. 14 Jungja shelter space at rural villages in Gyungbuk province, were investigated. An interview questionnaire was conducted for total 139 residents as POE. The use behavior and satisfaction for Jungja shelter space, were investigated. The statistical analysis were mean of satisfactions, reliability, factor analysis, and multiple regression analysis. The results and discussions can be objective data for rural village regeneration. In satisfaction level, 'Continuous use intention'(3.99), 'Well-suited approach'(3.87), and 'Helpful in resident living'(3.84) were shown to be high points of agreement in 5 point Likert type scale. But, the mean points were low as 2.01 in 'Surrounding landscape', 'Creation of green areas'(3.22), and 'Traffic safety'(3.22), respectively. Within use satisfaction, 5 factors were categorized, 'Use', 'Safety', 'Facility', 'Management' and 'Users'. By the result of multiple regression analysis, variables of 'Continuous use', 'Convenient location', and 'Image improvement', were shown to be main affecting variables to overall satisfaction. Furthermore, in spatial structure analysis, 4 types were categorized with the aspect of landform, roads, and location in village. The levels of satisfaction were shown to be high in village type of semi-open, road type of circular, and location type of center/back. Conclusively, these findings could be utilized as basic data and useful tool of space-structural satisfaction analytic method, and for each stage of planning/design and remodeling for rural village regeneration.

공간 밀도분석을 이용한 재정비 대상지 탐색에 관한 연구 (A Study on Exploring Urban Renewal Areas Using Spatial Density Analysis)

  • 김기중;고승욱;성진욱
    • 토지주택연구
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    • 제14권2호
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    • pp.35-50
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    • 2023
  • 정비사업에 있어 공공의 역할이 강조되고 있는 상황에서 객관적으로 정비사업이 필요한 지역을 선제적으로 살펴보는 것은 매우 중요하다. 이 연구의 목적은 공간데이터를 활용하여 재정비가 필요한 지역을 탐색하고, 재정비 대상지 유형화 및 특성을 분석하는 것이다. 이를 달성하기 위해 공간데이터를 사용하여 커널밀도함수와 K-means 군집분석을 수행하였고, 재정비 대상지역 발굴 방법을 모색하였다. 주요연구결과 및 시사점을 요약하면 다음과 같다. 첫째, 개발 용적비와 노후도 지표를 기준으로 서울시 전역에 걸쳐 587개 재정비 대상지를 구획하였으며, 선도사업·신속통합기획 후보지 비교결과 절반 정도 일치성을 확인하였다. 둘째, 재정비 대상지는 공공에서 지정한 선도사업 후보지에 비하여 상대적으로 주거환경이 열악하였다. 셋째, 재정비 대상지는 통계적으로 뚜렷하게 유형화되지 않았으며, 사업요건별 유형화의 타당성을 확인하였다.