• Title/Summary/Keyword: spatial sampling

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Geovisualization of Coastal Ocean Model Data Using Web Services and Smartphone Apps (웹서비스와 스마트폰앱을 이용한 연안해양모델 예측자료의 시각화시스템 구현)

  • Kim, Hyung-Woo;Koo, Bon-Ho;Woo, Seung-Buhm;Lee, Ho-Sang;Lee, Yang-Won
    • Spatial Information Research
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    • v.22 no.2
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    • pp.63-71
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    • 2014
  • Ocean leisure sports have recently emerged as one of so-called blue ocean industries. They are sensitive to diverse environmental conditions such as current, temperature, and salinity, which can increase needs of forecasting data as well as in-situ observations for the ocean. In this context, a Web-based geovisualization system for coastal information produced by model forecasts was implemented for use in supporting various ocean activities. First, FVCOM(Finite Volume Coastal Ocean Model) was selected as a forecasting model, and its data was preprocessed by a spatial interpolation and sampling library. The interpolated raster data for water surface elevation, temperature, and salinity were stored in image files, and the vector data for currents including speed and direction were imported into a distributed DBMS(Database Management System). Web services in REST(Representational State Transfer) API(Application Programming Interface) were composed using Spring Framework and integrated with desktop and mobile applications developed on the basis of hybrid structure, which can realize a cross-platform environment for geovisualization.

Spatial Distribution Pattern of the Populations of Carex siderosticta at Mt. Geumjeong and Mt. Ahop (금정산과 아홉산의 대사초 집단의 공간적 분포 양상)

  • Huh, Man Kyu
    • Journal of Life Science
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    • v.25 no.4
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    • pp.369-375
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    • 2015
  • Data on the spatial distribution of a plant population among administrative areas is useful for various purposes. In this study, I analyzed the spatial distribution of the geographical distances of Carex siderosticta at Mt. Geumjeong and Mt. Ahop in Korea. The aim was to test a spatial structure within two populations of C. siderosticta. Most natural plots of C. siderosticta are not uniformly distributed in the forest community; for example, uniform plots were aggregately distributed within a space of 6.0 m $\times$ 6.0 m. When the sampling plots were larger than 6.0 m $\times$ 12.0 m, the individuals of C. siderosticta were aggregately distributed. The neighboring patches of C. siderosticta were predominantly 7.5 m to 9.0 m apart, on average; however, if the natural populations were disturbed by human activities, the aggregation occurred in shorter distances than a scale of 9.0 m. Moran's I of C. siderosticta significantly differed from the expected value in only 16 of 40 cases (40%). In conclusion, the geographical distribution of C. siderosticta is not even, with varying degrees of size in the plots, while human activities give rise to density effects in the plots at both Mt. Geumjeong and Mt. Ahop in Korea.

Spatial Distribution of Dissolved Organic Matter Compositions Upstream of Ipobo (이포보 상류 용존 유기물의 공간적 분포 분석)

  • Yoon, Sang Mi;Choi, Jung Hyun
    • Journal of Korean Society on Water Environment
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    • v.34 no.4
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    • pp.399-408
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    • 2018
  • This research investigated the effects of weir (Ipobo) construction on the dynamics and the related spatial distributions of pollutants inflowing from tributaries (Yanghwacheon and Bokhacheon). Conductivity measurements and water sampling were conducted longitudinally, horizontally, and vertically in the waterbody upstream of the area located in Ipobo. Additionally, collected water samples were used for the dissolved organic carbon (DOC) analysis and fluorescence analysis which results in the SUVA, HIX, BIX, and FI calculation and parallel factor analysis (PARAFAC). Consequently, the results of the Conductivity, DOC, SUVA, and HIX showed that high concentration of pollutants that were flowing from the area of Bokhacheon which was mixed along the flow of the main river. The results of the BIX and FI did not show significant difference along the river flow which represented that allochthonous and terrestrial DOM, and for this reason was dominated in the whole waterbody rather than just the autochthonous DOM. The PARAFAC results showed that the two fluorescence components, humic-like and protein-like, constituted the fluorescence matrices of the water samples. The prevailing discipline notes that the two components were inflowing from the tributaries, however, a refractory component, humic-like substances, was relatively accumulated near the weir. From the results, the dynamics and spatial distributions of the DOM are dependent on the DOM characteristics, which induces the application of a specialized DOM analysis method to investigate the effects of a subsequent weir construction on the dynamics and spatial distributions of pollutants inflowing from the tributaries.

Genetic Diversity and Spatial Genetic Structure of Berchemia racemosa var. magna in Anmyeon Island (안면도 먹넌출 집단의 유전다양성과 공간적 유전구조)

  • Song, Jeong-Ho;Lim, Hyo-In;Jang, Kyeong-Hwan;Hong, Kyung-Nak;Han, Jingyu
    • Horticultural Science & Technology
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    • v.32 no.1
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    • pp.84-90
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    • 2014
  • Berchemia racemosa var. magna is only found in Anmyeon Island of South Korea. Genetic diversity and the spatial genetic structure of B. racemosa var. magna in Anmyeon Island were studied by I-SSR marker system. Fifty I-SSR amplicons were produced from 8 selected primers. We used 13 polymorphic markers to analyze the genetic structure. Distribution of 39 individuals in the study plot($90m{\times}70m$) showed aggregate pattern (aggregation index = 0.706). Total 21 genets were observed from 39 individuals through I-SSR genotyping. Proportion of distinguishable genotype (G/N), genotype diversity (D) and genotype evenness (E) were 53.8%, 0.966 and 0.946, respectively. In spite of the small number and the narrow distribution, Shannon's diversity index (I = 0.598) was relatively high as compared with those of the other plant species. For ex situ genetic conservation of B. racemosa var. magna, the sampling strategy based on spatial autocorrelation using Tanimoto distance is efficient at choosing the conserved individuals with a 6 meter interval between individual trees.

Genetic Diversity and Spatial Genetic Structure of Dwarf Stone Pine in Daecheongbong Area, Mt. Seorak (설악산 대청봉 눈잣나무(Pinus pumila (Pall.) Regel) 집단의 유전다양성과 공간적 유전구조)

  • Song, Jeong-Ho;Lim, Hyo-In;Hong, Kyung-Nak;Jang, Kyung-Hwan;Hong, Yong-Pyo
    • Korean Journal of Plant Resources
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    • v.25 no.4
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    • pp.407-415
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    • 2012
  • Pinus pumila, which occurs in the northeast Asia, is found limitedly in Daecheongbong area of Mt. Seorak in the South Korea. This population was chosen to study spatial pattern, genetic diversity and spatial genetic structure. There were 48 polymorphic and 30 monomorphic I-SSR markers. A total of 65 individuals which distributed in the study site (40 m ${\times}$ 70 m) showed weakly aggregate distribution (Aggregate Index = 0.871). A total of 40 genets were observed from 65 individuals through I-SSR genotype comparison. Proportion of distinguishable genotype (G/N), genotype diversity (D) and genotype evenness (E) were 61.5%, 0.977 and 0.909, respectively. In spite of the small number and the limited distribution, Shannon's diversity index (I = 0.567) was relatively high as compared with those of other plant species. Spatial autocorrelation using Tanimoto's distance showed that the genetic patch was established within 12 m. Based on Mantel tests, there was relatively low correlation between genetic distance and geographic distance. Therefore, it seems the P. pumila population was formed by many parent trees in early stage. For ex situ genetic conservation of P. pumila, the sampling strategy is efficient at least above 12 m between individual trees.

Applying Spitz Trace Interpolation Algorithm for Seismic Data (탄성파 자료를 이용한 Spitz 보간 알고리즘의 적용)

  • Yang Jung Ah;Suh Jung-Hee
    • Geophysics and Geophysical Exploration
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    • v.6 no.4
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    • pp.171-179
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    • 2003
  • In land and marine seismic survey, we generally set receivers with equal interval suppose that sampling interval Is too narrow. But the cost of seismic data acquisition and that of data processing are much higher, therefore we should design proper receiver interval. Spatial aliasing can be occurred on seismic data when sampling interval is too coarse. If we Process spatial aliasing data, we can not obtain a good imaging result. Trace interpolation is used to improve the quality of multichannel seismic data processing. In this study, we applied the Spitz algorithm which is widely used in seismic data processing. This algorithm works well regardless of dip information of the complex underground structure. Using prediction filter and original traces with linear event we interpolated in f-x domain. We confirm our algorithm by examining for some synthetic data and marine data. After interpolation, we could find that receiver intervals get more narrow and the number of receiver is increased. We also could see that continuity of traces is more linear than before Applying this interpolation algorithm on seismic data with spatial aliasing, we may obtain a better migration imaging.

Measurement of Imaging Property of Flat-Panel Detector

  • Matsumoto, Masao;Suekane, Kouji;Maeda, Kouji;Ogata, Yuji;Inamura, Kiyonari;Kanai, Kouzo;Kanamori, Hitoshi
    • Proceedings of the Korean Society of Medical Physics Conference
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    • 2002.09a
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    • pp.385-388
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    • 2002
  • We measured and evaluated digital, pre-sampling and overall imaging properties (characteristic curves, Modulation Transfer Function (MTF), Wiener spectra (WS), Noise Equivalent Quanta (NEQ) and Detective Quantum Efficiency (DQE)) for the direct type and indirect type of Flat-Panel Detector (FPD). First, the digital and overall characteristic curves of the both types of FPD had more wide dynamic range than that of the S/F system. Second, the pre-sampling and overall MTF of the direct-type FPD were superior to those of the indirect-type FPD. Third, for identical exposures, the digital and overall WS of the direct-type FPD were similar or worse than those of the indirect-type FPD, and for larger exposure, the digital WS of the both types of FPD were smaller, but overall WS of the both types of FPD were larger. Fourth, the digital and overall NEQ and DQE of the direct-type FPD were worse than both NEQ and DQE of the indirect-type FPD at lower spatial frequencies, but were better at higher spatial frequencies.

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A Framework for Quality Evaluation of Geospatial Data (Geospatial Data의 품질평가를 위한 Framework)

  • Cho, Gi-Sung
    • Journal of Korean Society for Geospatial Information Science
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    • v.4 no.2 s.8
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    • pp.123-136
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    • 1996
  • Lately, the demand for data standardization become increased to obtain various data jointly along with development of information technology and diversity of society. Thus the research on tile definition and evaluation of data quality indicating accuracy and confidence of geospatial data, is required for this standardization. In this study, by virtue of comparison of definitions and evaluation methods of data quality element being selected from representative countries, the following results were obtained: (1) Application of ISO/TC211's Draft having accepted evaluation standard to KSDTS(Korea Spatial Data Transfer Standard) is desirable for definitions of data quality elements. (2) This study presented the quality evaluation of much more resonable geospatial data accompaning with quality element. Furthermore, this study suggests that this evaluation be applicable to KSDTS and be contained in the digital map product specification of National Geography Institute with more clearness of a report form of data quality evaluation result. (3) Studies on various sampling methods, establishment of AQL(Acceptable Quality Level) suitable for our country, and computer programming which can rapidly and automatically evaluate mass much of data are required.

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Errors in Estimated Temporal Tracer Trends Due to Changes in the Historical Observation Network: A Case Study of Oxygen Trends in the Southern Ocean

  • Min, Dong-Ha;Keller, Klaus
    • Ocean and Polar Research
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    • v.27 no.2
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    • pp.189-195
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    • 2005
  • Several models predict large and potentially abrupt ocean circulation changes due to anthropogenic greenhouse-gas emissions. These circulation changes drive-in the models-considerable oceanic oxygen trend. A sound estimate of the observed oxygen trends can hence be a powerful tool to constrain predictions of future changes in oceanic deepwater formation, heat and carbon dioxide uptake. Estimating decadal scale oxygen trends is, however, a nontrivial task and previous studies have come to contradicting conclusions. One key potential problem is that changes in the historical observation network might introduce considerable errors. Here we estimate the likely magnitude of these errors for a subset of the available observations in the Southern Ocean. We test three common data analysis methods south of Australia and focus on the decadal-scale trends between the 1970's and the 1990's. Specifically, we estimate errors due to sparsely sampled observations using a known signal (the time invariant, temporally averaged, World Ocean Atlas 2001) as a negative control. The crossover analysis and the objective analysis methods are for less prone to spatial sampling location biases than the area averaging method. Subject to numerous caveats, we find that errors due to sparse sampling for the area averaging method are on the order of several micro-moles $kg^{-1}$. for the crossover and the objective analysis method, these errors are much smaller. For the analyzed example, the biases due to changes in the spatial design of the historical observation network are relatively small compared to the tends predicted by many model simulations. This raises the possibility to use historic oxygen trends to constrain model simulations, even in sparsely sampled ocean basins.

Seasonal and Spatial Diversity of Picocyanobacteria Community in the Great Mazurian Lakes Derived from DGGE Analyses of 16S rDNA and cpcBA-IGS Markers

  • Jasser, Iwona;Krolicka, Adriana;Jakubiec, Katarzyna;Chrost, Ryszard J.
    • Journal of Microbiology and Biotechnology
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    • v.23 no.6
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    • pp.739-749
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    • 2013
  • The seasonal and spatial diversity of picocyanobacteria (Pcy) in lakes of the Great Mazurian Lakes (GLM) system was examined by DGGE analysis of molecular markers derived from the 16S-23S internal transcribed spacer (ITS) of the ribosomal operon and the phycocyanin operon (cpcBA-IGS). The study of nine lakes, ranging from mesotrophy to hypereutrophy, demonstrated seasonal variance of Pcy. The richness and Shannon diversity index calculated on the basis of both markers were higher in spring and lower in early and late summer. No statistically significant relationships were found between the markers and trophic status of the studied lakes or Pcy abundance. There were, however, statistically significant relationships between the diversity indices and sampling time. The analysis pointed to a different distribution of the two markers. The ITS marker exhibited more unique sequences in time and space, whereas a greater role for common and ubiquitous sequences was indicated by the cpcBA-IGS data. Examination of the Pcy community structure demonstrated that communities were grouped in highly similar clusters according to sampling season/time rather than to the trophic status of the lake. Our results suggest that time is more important than trophic status in shaping the diversity and structure of Pcy communities. The seasonal changes in picocyanobacteria and differences in diversity and community structures are discussed in the context of well-established ecological hypotheses: the PEG model, intermediate disturbance hypothesis (IDH), and horizontal gene transfer (HGT).