• Title/Summary/Keyword: 반분산

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Spatial Analysis of Flood Rainfall Based on Kriging Technique in Nakdong River Basin (크리깅 기법을 이용한 낙동강 유역 홍수강우의 공간해석 연구)

  • Yoon, Kang-Hoon;Seo, Bong-Chul;Shin, Hyun-Suk
    • Journal of Korea Water Resources Association
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    • v.37 no.3
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    • pp.233-240
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    • 2004
  • Most of hydrological analyses in the field of water resources are launched by gathering and analyzing rainfall data. Several methods have been developed to estimate areal rainfall from point rainfall data and to fill missing or ungaged data. Thiessen and Reciprocal Distance Squared(RDS) methods whose parameters are only dependent on inter-station distance are classical work in hydrology, but these techniques do not provide a continuous representation of the hydrologic process involved. In this study, kriging technique was applied to rainfall analysis in Nakdong river basin in order to complement the defects of these classical methods and to reflect spatial characteristics of regional rainfall. After spatial correlation and semi-variogram analyses were performed to perceive regional rainfall property, kriging analysis was performed to interpolate rainfall data for each grid Thus, these procedures were enable to estimate average rainfall of subbasins. In addition, poor region of rainfall observation was analyzed by spatial interpolation error for each grid and mean error for each subbasin.

The Hierarchical Interpolation of the Coastal Echo Sounding Data (연안 해역 음향 측심 자료의 계층적 보간)

  • 이석찬;이창경
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.9 no.1
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    • pp.63-73
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    • 1991
  • The data type of the echo sounding for the contouring of coastal chart is continuous profiles, and there are no data between the profiles. In this study, at first, the depths of the regular grid along the sounding line were interpolated by linear equation. After that the depths of the regular grid located between the profiles were interpolated by kriging. The semivariogram contributes to the weight of interpolation. After comparison with the conventional Moving Average and Kriging, it turns out that this algorithm shows merits in the field of the accuracy and computing time.

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Spatial Characteristics of Gwangneung Forest Site Based on High Resolution Satellite Images and DEM (고해상도 위성영상과 수치고도모형에 근거한 광릉 산림 관측지의 공간적 특성)

  • Moon Sang-Ki;Park Seung-Hwan;Hong Jinkyu;Kim Joon
    • Korean Journal of Agricultural and Forest Meteorology
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    • v.7 no.1
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    • pp.115-123
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    • 2005
  • Quantitative understanding of spatial characteristics of the study site is a prerequisite to investigate water and carbon cycles in agricultural and forest ecosystems, particularly with complex, heterogeneous landscapes. The spatial characteristics of variables related with topography, vegetation and soil in Gwangneung forest watershed are quantified in this study. To characterize topography, information on elevation, slope and aspect extracted from DEM is analyzed. For vegetation and soil, a land-cover map classified from LANDSAT TM images is used. Four satellite images are selected to represent different seasons (30 June 1999, 4 September 2000, 23 September 2001 and 14 February 2002). As a flux index for CO₂ and water vapor, normalized difference vegetation index (NDVI) is calculated from satellite images for three different grid sizes: MODIS grid (7km x 7km), intensive observation grid (3km x 3km), and unit grid (1km x 1km). Then, these data are analyzed to quantify the spatial scale of heterogeneity based on semivariogram analysis. As expected, the scale of heterogeneity decreases as the grid size decreases and are sensitive to seasonal changes in vegetation. For the two unit grids where the two 40 m flux towers are located, the spatial scale of heterogeneity ranges from 200 to 1,000m, which correspond well to the climatology of the computed tower flux footprint.

The Study of Reliability and Validity of Attention Deficit Disorder Evaluation Scale-School Version(ADDES-SV) (주의력결핍 과잉운동장애 아동 평가척도의 교사 평가판에 대한 신뢰도 및 타당도 연구)

  • Bae, Jin-Woo;Cheung, Seung-Douk;Lee, Jong-Bum;Park, Hyung-Bae;Kim, Jin-Seung;Song, Chang-Jin
    • Journal of Yeungnam Medical Science
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    • v.14 no.2
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    • pp.415-429
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    • 1997
  • The purpose of this study was to examine the reliability and validity of attention deficit disorder evaluation scale-school version(ADDES-SV). Between October 1996 and November 1996, ADDES-SV was administered to 263 elementary school students in the second grade and between Jun 1996 and October 1996, 28 attention deficit hyperactivity disorder patients. In the reliability test, the test-retest reliability coefficient was significantly high and that of inattention was 0.88, that of impulsivity was 0.80, that of hyperactivity was 0.83 and total score was 0.83. In the reliability test by internal consistancy, the Cronbach $\alpha$ coefficient was significantly high and that of inattention was 0.98, that of impulsivity was 0.87, that of hyperactivity was 0.87(p<0.05). The half-sprit reliability coefficient by first-second half method showed high correlation and that of inattention was part 1: 0.96, part 2: 0.96 impulsivity was part 1: 0.95, part 2: 0.93, hyperactivity was part 1: 0.92, part 2: 0.94(p<0.05). Inter-rater reliability by pearson correlation coefficient was significantly high and that of inattention was 0.92, that of impulsivity was 0.87, that of hyperactivity was 0.89 and total score was 0.89. The concurrent validity between ADDES-SV and CAP scale was 0.85 in attention deficit hyperactivity disorder patient group and 0.79 in normal control group(p<0.05). In discriminant validity test between attention deficit hyperactivity disorder patient group and normal control group, the patient group showed higher score(p<0.05). The total discriminant capacity of the patient group in ADDES-SV was 94.6%. In this point of view, ADDES-SV scale showed high reliability and validity in applying to Korean subjects and was proved to be the useful screening test tool for attention deficit hyperactivity disorder research.

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Discussions on the Distribution and Genesis of Mountain Ranges in the Korean Peninsular (II) : The Proposal of 'Sanjulgi-Jido(Mountain Ridge Map)‘ (한국 산맥론(II): 한반도 '산줄기 지도'의 제안)

  • Park Soo Jin;SON ILL
    • Journal of the Korean Geographical Society
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    • v.40 no.3 s.108
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    • pp.253-273
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    • 2005
  • In recent years, there are strong social demands to characterize the spatial distribution of mountains in Korea. This study aims to develop a 'Sanjulgi-Jido(mountain ridge map)' that might be used not only to satisfy these social demands but also to effectively present the spatial distribution of mountains and drainage basins in the Korean Peninsular. The 'Sanjulgi-Jido' developed in this study is a map that presents the continuity of mountains based on the drainage divides that are delineated by a pre-defined drainage basin size and elevation. This study first validated the Bakdudaegan system through the analyses of a digital elevation model. The Bakdudaegan system has long been recognized as the Koreans traditional conceptual framework to characterize the spatial distribution of mountains. The analyses showed that the Bakdudaegan system has several problems to represent the mountain systems in Korea, which includes 1) the lack of the representativeness of drainage basins, 2) inaccuracy to depict the boundary of drainage basins, 3) the lack of representativeness of mountains, and 4) geo-polical issue that confines the spatial extent of mountain systems within the Korean Peninsular. In order to represent the mountains system in a more quantitative manner, we applied several terrain analysis techniques to understand the spatial distribution of mountains and drainage basins. Based on these analyses, we developed an hierarchical system to classify the continuity (If mountains, which are presented as the spatial distribution of drainage divides with a certain elevation. The first-order Sanjulgi is the drainage divides whose drainage basin are bigger than $5,000km^2$ and the point elevation is above 100m. The next order Sanjulgi is delineated as the size of drainage basin is successively divided by two. This kind of design is able to provide a logical framework to present the mountain systems at different details, depending on the purpose and scale of maps. We also provide several empirical functions to calculate various geomorphological indices for each order of Sanjulgi. The 'Sanjulgi Jido' is similar with the Bakdudaegan system, since it characterizes the continuity of mountains based on the spatial distribution of the drainage divide. It, however, has more scientific criteria to define the scale and continuity of mountains. It should be also noted that the 'Sanjulgi Jido' proposed has different logical and methodological background, compared with the mountain range map that explains the genesis of mountain systems in addition to the continuity of mountains.