• Title/Summary/Keyword: SCDS

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Nondestructive Nutrient Diagnosis for Nitrogen with Specific Color Difference Sensor(SCDS) in Hydroponics of Tomato (Lycopersicon esculentum MILL.) (토마토 양액 재배시 비파괴 간이 질소 영양 진단)

  • 이용범;노미영;조영렬;배종향
    • Journal of Bio-Environment Control
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    • v.4 no.2
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    • pp.175-180
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    • 1995
  • This study was conducted to establish the nondestructive nutrient diagnosis method for nitrogen in tomato leaf using SCDS(specific color difference sensor). NFT(nutrient film technique) system was used in this experiment and nitrogen concentrations treated in nutrient solution were 0, 10, 50, 100, 150, 200, 300 and 600ppm. As nitrogen concentration in nutrient solution was increased from 0ppm to 150ppm, the stomatal resistance of tomato leaf was decreased abruptly, the $CO_2$ assimilation rate was increased but there was no big difference in the range of 100-500ppm. As the SCDS value of tomato leaf was increased, the $CO_2$ assimilation rate was increased linearly but the total average fruit weight and marketable yield were increased quadratically. The $CO_2$ assimilation rate was largely increased in the 0-3% range of leaf nitrogen content, but photosynthetic saturation was shown in 3.3-3.5%. The leaf nitrogen content was closely related to SCDS value of tomato leaf. Considering physiological activity, growth and yield of tomato, the optimum ranges of leaf nitrogen content were found to be 3.0-3.8% and the SCDS values equivalent for those ranges were 40.0-52.2.

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An Efficient Application of XML Schema Matching Technique to Structural Calculation Document of Bridge (XML 스키마 매칭 기법의 교량 구조계산서 적용 방안)

  • Park, Sang Il;Kim, Bong-Geun;Lee, Sang-Ho
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.32 no.1D
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    • pp.51-59
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    • 2012
  • An efficient application method of XML schema matching technique to the document structure of structural calculation document (SCD) of bridge is proposed. With 30 case studies, a parametric study on weightings of name, sibling, child, and parent elements of XML scheme component that are used in the similarity measure of XML schema matching technique has been performed, and suitable weighting to analyze document structure of SCD is suggested. A simplified formula for quantification of similarity is also introduced to reduce computation time in huge scale document structure of SCDs. Numerical experiments show that the suggested method can increase the accuracy of XML schema matching by 10% with suitable weighting parameters, and can maintain almost the same accuracy without weighting parameters compared to previous studies. In addition, computation time can be reduced dramatically when the proposed simplified formula for the quantification of similarity is used. In the numerical experiments of testing 20 practical SCDs of bridges, the suggested method is superior to previous studies in the accuracy of analyzing document structure and 4 to 460 times faster than the previous results in computation time.

2-dimensional Mapping of Sulfur Dioxide and Bromine Oxide at the Sakurajima Volcano with a Ground Based Scanning Imaging Spectrograph System

  • Lee, Han-Lim;Kim, J.-Hoon;Ryu, Jae-Yong;Kwon, Soon-Chul;Noh, Young-Min;Gu, Myo-Jeong
    • Journal of the Optical Society of Korea
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    • v.14 no.3
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    • pp.204-208
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    • 2010
  • A scanning imaging spectrograph system was used in this study to retrieve readings of the 2-D distribution of $SO_2$ and BrO around the crater of the Sakurajima volcano in Japan. The measurement was carried out during the daytime on November 2, 2005. Measurements were made at the surface of the site, located 5 km from the Sakurajima crater. One hundred horizontal scans were performed. Each column scanned by the system consists of 64 vertical pixels in order to retrieve the spatial distributions of BrO and $SO_2$ in the plume in terms of slant column densities (SCDs). Measured spectra were analyzed to identify and quantify $SO_2$ and BrO in the volcanic plume utilizing the plume's specific absorption features in the ultra violet region. Two-dimensional BrO and $SO_2$ distributions in SCD were retrieved horizontally covering the upwind, crater and downwind areas, and vertically, including the plume in the center of the scanned image. Both horizontal and vertical dispersions of $SO_2$ SCD from the crater were successfully measured to be from $10^{17}$ to $4.5{\times}10^{18}$ molecules $cm^{-2}$. However, BrO was measured below $10^{15}$ molecules $cm^{-2}$, which is considered its background level.

Spectrum Sensing with Combining Spectral Correlation Density for ATSC Signal Detection (ATSC 신호 검출을 위한 스펙트럴 상관 밀도의 결합을 이용하는 스펙트럼 센싱)

  • Yoo, Do-Sik;Lim, Jongtae
    • Journal of Advanced Navigation Technology
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    • v.17 no.3
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    • pp.298-305
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    • 2013
  • In this paper, we propose simple combining schemes for sensing ATSC digital television signals with spectral correlation density (SCD). The detection algorithms exploiting the cyclostationarity exhibited by the pilot of ATSC digital television signals usually use the SCD value at a given particular frequency. However, we found that non-zero SCDs are found to be distributed over a certain range of frequencies in multipath fading environment. To utilize a set of non-zero SCD values computed in the vicinity of the pilot location, we formulate a class of combining methods in analogy with the maximal ratio combining, the square law combining and the equal gain combining. We show that the proposed simple combining schemes improve the detection performance by 0.5~1.0dB under multipath fading environments.