• Title/Summary/Keyword: Spatial Statistics

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A development of multisite hourly rainfall simulation technique based on neyman-scott rectangular pulse model (Neyman-Scott Rectangular Pulse 모형 기반의 다지점 강수모의 기법 개발)

  • Moon, Jangwon;Kim, Janggyeong;Moon, Youngil;Kwon, Hyunhan
    • Journal of Korea Water Resources Association
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    • v.49 no.11
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    • pp.913-922
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    • 2016
  • A long-term precipitation record is typically required for establishing the reliable water resources plan in the watershed. However, the observations in the hourly precipitation data are not always consistent and there are missing values within the time series. This study aims to develop a hourly rainfall simulator for extending rainfall data, based on the well-known Neyman-Scott Rectangular Pulse Model (NSRPM). Moreover, this study further suggests a multisite hourly rainfall simulator to better reproduce areal rainfalls for the watershed. The proposed model was validated with a network of five weather stations in the Uee-stream watershed in Seoul. The proposed model appeared a reasonable result in terms of reproducing most of the statistics (i.e. mean, variance and lag-1 autocovariance) of the rainfall time series at various aggregation levels and the spatial coherence over the weather stations.

Characteristics of Firms Related to the Products for the Elderly: Sectoral and Spatial Policy Implications with the Exploration of the Types of Firms (고령친화용품산업의 현황과 특성: 기업 유형별 탐색을 통한 산업 및 공간 정책에의 시사점)

  • Park, Sam-Ock;Koo, Yang-Mi;Jin, Jong-Heon
    • Journal of the Economic Geographical Society of Korea
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    • v.12 no.1
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    • pp.1-18
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    • 2009
  • The aim of this study is to analyze the characteristics of firms related to products for the elderly. The data are based on statistics, questionnaire surveys and interviews with the persons related to the industry. Firms are classified into $3\times3$ matrix with the indexes of innovation performance and network participation. The former is measured with the number of patents and the latter is evaluated by the degree centrality of firms' network in the industries. Combining the previous indexes with other properties, the 9 categories are merged into 5 types: 'High Performance-High Centrality' (HP-HC), 'Network Leader-Low Technology Manufacturer' (NL-LTM), 'Network Leader-Distributor' (NL-D), 'High Performance-Network Outsider' (HP-NO), 'Low Performance-Isolated' (LP-I). Finally, sectoral and spatial policy implications are explored with the results of analysis.

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Recent Spatio-temporal Changes of Landscape Structure, Heterogeneity and Diversity of Rural Landscape: Implements for Landscape Conservation and Restoration (한국 농산촌 경관의 구조와 이질성 및 다양성의 최근 변화: 경관의 보전과 복원과의 관계)

  • Hong, Sun-Kee;Rim, Young-Deuk;Nakagoshi, Nobukazu;Chang, Nam-Kee
    • The Korean Journal of Ecology
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    • v.23 no.5
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    • pp.359-368
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    • 2000
  • Landscape change is the modification and replacement of landscape elements in accordance with human management and natural disturbance on land mosaics. During landscape change, changes in patterns such as heterogeneity, diversity and shape, and juxtaposition of spatial elements are also accompanied. For the sustainable landscape system, therefore, spatial characteristics of the landscape should be considered in implementation of landscape conservation and restoration planning. Short-term changes of land-use and landscape pattern during the 10 years of 1980s and 1990s were investigated in the agriculture-forestry dominated landscape system through the statistics and the analysis of landscape-vegetation map. Study area is Yangdong-myon, Yangpyung-gun (37°27′30"N, 127°46′50"E), Kyonggi-do, in central Korea. Landscape change of this region was significantly related to the recent industrialization according to socio-economic development. Analyses of landscape pattern show that the area of secondary forest sustained by human activity decreased and it was replaced with large exotic plantations during this period. Area of paddy field was also extended. Fractal dimension of the total landscape increased, but that of paddy field area decreased due to rearrangement for mechanized farming. Moreover, the area of landscape management regimes such as plantation and cultivation increased in land mosaics during this period.

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Near-Infrared Spectral Characteristics in Presence of Sun Glint Using CASI-1500 Data in Shallow Waters

  • Jeon, Joo-Young;Kim, Sun-Hwa;Yang, Chan-Su
    • Korean Journal of Remote Sensing
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    • v.31 no.4
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    • pp.281-291
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    • 2015
  • Sun glint correction methods of hyperspectral data that have been developed so far have not considered the various situations and are often adequate for only certain conditions. Also there is an inaccurate assumption that the signal in NIR wavelength is zero. Therefore, this study attempts to analyze the NIR spectral properties of sun glint effect in coastal waters. For the analysis, CASI-1500 airborne hyperspectral data, bathymetry data and in-situ data obtained at coastal area near Sin-Cheon, Jeju Island, South Korea were used. The spectral characteristics of radiance and reflectance at the five NIR wavelengths (744 nm, 758 nm, 772 nm, 786 nm, and 801 nm) are analyzed by using various statistics, spatial and spectral variation of sun-glinted area under conditions of the bottom types of benthos, barren rocks and sand with similar water depth. Through the quantitative analysis, we found that the relation of water depth or bottom type with sun glint is relatively less which is a similar result with the previous studies. However the sun glint are distributed similarly with the patterns of the direction of wave propagation. It is confirmed that the areas with changed direction of wave propagation were not affected by the sun glint. The spatial and spectral variations of radiance and reflectance are mainly caused by the effect of sun glint and waves. The radiance or reflectance of more sun-glinted areas are increased approximately 1.5 times and the standard deviations are also increased three times compared to the less sun glinted areas. Through this study, the further studies of sun glint correction method in coastal water using the patterns of wave propagation and diffraction will be placed.

Landscape Elements and User Satisfaction in National Street: Focusing on Gwangwhamun Square (국가상징거리의 구성요소 특징과 만족도에 관한 연구: 광화문 광장을 중심으로)

  • Choi, Hyun-Ah;Cho, Young-Tae;Lee, Woo-Kyun
    • Land and Housing Review
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    • v.5 no.4
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    • pp.215-224
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    • 2014
  • National street has become one of open space for enhancing environmental qualities of city and country. In the developed countries such as France, U.K. U.S.A are designed symbolic malls, squares and street which are represented the historicity, culture and symbolic place. For place identity, we analyzed the relationship between element and user satisfaction in Sejong Avenue, Gwangwhamun Square. Data were analyzed using statistical methods such as descriptive statistics, ANOVA and correlation. Results of this study are as follows, i) factor analysis is carried out to extract spatial components and satisfaction. The satisfaction concerning transportation access was the higher than other factors, ii) user satisfaction was strongly correlated on the spatial elements, iii) user showed high user perception to study site. Results of this study can identify representative street management plan based on landscape elements and user satisfaction.

Implementation of Open Source SOLAP Decision-Making System for Livestock Epidemic Surveillance and Prevention (Open Source SOLAP기반의 가축전염병 예찰 및 방역 의사결정 지원시스템 구현)

  • Kyung, Min-Ju;Yom, Jae-Hong
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.30 no.3
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    • pp.287-294
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    • 2012
  • The spread of infectious diseases in the event of livestock is getting faster and the route of spread gets more varied. It is important for the responsible agency to detect early and establish a prevention and surveillance system. If the spread cannot be contained effectively, great damage and loss will be inevitable in terms of social, environment and economic aspects as well as the welfare of the farmers. At present in Korea, a web-based Infectious Livestock Diseases Statistics System (AIMS: Animal Infectious Disease Data Management System) has been already implemented for this purpose and the service is available to the general public. But this system does not provide geospatial information and does not provide support for decision making and does not provide multi-dimensional information. In this study, an open source-based SOLAP (Spatial On-Line Analytical Processing) technology is applied to enable many diverse forms of data analysis from many aspects to support decision making. The SOLAP system was designed to integrate geospatial information and the analysis of information has been largely divided into map-based analysis and table-based analysis.

Analysis and Verification of Slope Disaster Hazard Using Infinite Slope Model and GIS (무한사면해석기법과 GIS를 이용한 사면 재해 위험성 분석 및 검증)

  • 박혁진;이사로;김정우
    • Economic and Environmental Geology
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    • v.36 no.4
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    • pp.313-320
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    • 2003
  • Slope disaster is one of the repeated occurring geological disasters in rainy season resulting in about 23 human losses in Korea every year. The slope disaster, however, mainly depends on the spatial and climate properties. such as geology, geomorphology, and heavy rainfall, and, hence, the prediction or hazard analysis of the slope disaster is a difficult task. Therefore, GIS and various statistical methods are implemented for slope disaster analysis. In particular, GIS technique is widely used for the analysis because it effectively handles large amount of spatial data. The GIS technique. however, only considers the statistics between slope disaster occurrence and related factors, not the mechanism. Accordingly. an infinite slope model that mechanically considers the balance of forces applied to the slope is suggested here with GIS for slope disaster analysis. According to the research results, the infinite slope model has a possibility that can be utilized for landslide prediction and hazard evaluation since 87.5% of landslide occurrence areas have been predicted by this technique.

Population Distribution Estimation Using Regression-Kriging Model (Regression-Kriging 모형을 이용한 인구분포 추정에 관한 연구)

  • Kim, Byeong-Sun;Ku, Cha-Yong;Choi, Jin-Mu
    • Journal of the Korean Geographical Society
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    • v.45 no.6
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    • pp.806-819
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    • 2010
  • Population data has been essential and fundamental in spatial analysis and commonly aggregated into political boundaries. A conventional method for population distribution estimation was a regression model with land use data, but the estimation process has limitation because of spatial autocorrelation of the population data. This study aimed to improve the accuracy of population distribution estimation by adopting a Regression-Kriging method, namely RK Model, which combines a regression model with Kriging for the residuals. RK Model was applied to a part of Seoul metropolitan area to estimate population distribution based on the residential zones. Comparative results of regression model and RK model using RMSE, MAE, and G statistics revealed that RK model could substantially improve the accuracy of population distribution. It is expected that RK model could be adopted actively for further population distribution estimation.

Cancer cluster detection using scan statistic (스캔 통계량을 이용한 암 클러스터 탐색)

  • Han, Junhee;Lee, Minjung
    • Journal of the Korean Data and Information Science Society
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    • v.27 no.5
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    • pp.1193-1201
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    • 2016
  • In epidemiology or etiology, we are often interested in identifying areas of elevated risk, so called, hot spot or cluster. Many existing clustering methods only tend to a result if there exists any clustering pattern in study area. Recently, however, lots of newly introduced clustering methods can identify the location, size, and shape of clusters and test if the clusters are statistically significant as well. In this paper, one of most commonly used clustering methods, scan statistic, and its implementation SaTScan software, which is freely available, will be introduced. To exemplify the usage of SaTScan software, we used cancer data from the SEER program of National Cancer Institute of U.S.A.We aimed to help researchers and practitioners, who are interested in spatial cluster detection, using female lung cancer mortality data of the SEER program.

Development of Vehicle Emission Model with a High Resolution in Time and Space (${\cdot}$공간적 고해상도 자동차 배출량 모형의 개발)

  • Park, Seong-Kyu;Kim, Shin-Do;Park, Ki-Hark
    • Journal of Environmental Health Sciences
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    • v.30 no.3
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    • pp.293-299
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    • 2004
  • Traffic represents one of the largest sources of primary air pollutants in urban area. As a consequence, numerous abatement strategies are being pursued to decrease the ambient concentration of pollutants. A characteristics of most of the these strategies is a requirement for accurate data on both the quantity and spatial distribution of emissions to air in the form of an atmospheric emission inventory database. In the case of traffic pollution, such an inventory must be compiled using activity statistics and emission factors for vehicle types. The majority of inventories are compiled using passive data from either surveys or transportation models and by their very nature tend to be out-of-date by the time they are compiled. The study of current trends is towards integrating urban traffic control systems and assessments of the environmental effects of motor vehicles. In this study, a model of vehicle emission calculation by using real-time traffic data was studied. Traffic data, which are required on a street-by-street basis, is obtained from induction loops of traffic control system. It is possible that characteristics of hourly air pollutants emission rates is obtained from hourly traffic volume and speed. An emission rates model is allocated with a high resolution space by using geographic information system (GIS). Vehicle emission model was developed with a high resolution spatial, gridded and hourly emission rates.