• Title/Summary/Keyword: fundamental research

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Compensation of Surface Temperature Effect in Determination of Sugar Content of Shingo Pears using NIR (근적외선을 이용한 신고 배 당도판정에 있어 표면 온도영향의 보정)

  • 이강진;최규홍;김기영;최동수
    • Journal of Biosystems Engineering
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    • v.27 no.2
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    • pp.117-124
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    • 2002
  • This research was conducted to develop a method to remove the effect of surface temperature of Shingo pears for sugar content measurement. Sugar content was measured by a near-infrared spectrum analysis technique. Reflected spectrum and sugar content of a pear were used for developing regression models. For the model development, reflected spectrums having wavelengths in the range of 654 to 1,052nm were used. To remove the effect of surface temperature, special sample preparation techniques and partial least square (PLS) regression models were proposed and tested. 71 Shingo pears stored in a cold storage, which had 2$^{\circ}C$ inside temperature, were taken out and left in a room temperature for a while. Temperature and reflected spectrum of each pear was measured. To increase the temperature distribution of samples, temperature and reflected spectrum of each pear was measured four times with one hour twenty minutes interval. During the experiment, temperature of pears increased up to 17 $^{\circ}C$. The total number of measured spectrum was 284. Three groups of spectrum data were formed according to temperature distribution. First group had surface temperature of 14$^{\circ}C$ and total number of 51. Second group consisted of the first and the fourth experiment data which contained the minimum and the maximum temperatures. Third group consisted of 155 data with normal temperature-distribution. The rest data set were used for model evaluation. Results shelved that PLS model I, which was developed by using the first data group, was inadequate for measuring sugar content of pears which had different surface temperatures from 14$^{\circ}C$. After temperature compensation, sugar content predictions became close to the measured values. Since using many data which had wide range of surface temperatures, PLS model II and III were able to predict sugar content of pears without additional temperature compensation. PLS model IV, which included the surface temperatures as an independent variable. showed slightly improved performance(R$^2$=0.73). Performance of the model could be enhanced by using samples with more wide range of temperatures and sugar contents.

Impressions on the Centennial Seminar of Korean Railroad

  • Tarumi, Hisashi
    • Journal of the Korean Society for Railway
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    • v.2 no.3
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    • pp.3-4
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    • 1999
  • Congratulations on the success of the Centennial seminar. I am much pleased to be invited to the memorable seminar and I would like to express my sincere gratitude to Korean members' hospitality. My main impressions for this visit to Korea are as follows : (omitted)

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SPECTRAL PROPERTIES OF GALACTIC AND EXTRAGALACTIC BLACK HOLE CANDIDATES

  • CHAKRABARTI SANDIP K.
    • Journal of The Korean Astronomical Society
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    • v.29 no.spc1
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    • pp.223-225
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    • 1996
  • We review current theoretical understanding of the spectral properties (low and high states, transition of states, quasi-periodic oscillations etc.) of the low mass as well as supermassive black hole candidates.

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Evaluation of Fundamental Period of Rockfill Dam Using Blasting Vibration Test (발파진동실험을 이용한 사력댐의 고유주기 산정)

  • Kim, Nam-Ryong;Ha, Ik-Soo
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.32 no.5C
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    • pp.185-192
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    • 2012
  • The objective of this study is to present and verify a method for evaluating the fundamental period of a rockfill dam using artificially generated vibration from a blasting event. In this study, the artificial blasting vibration tests were carried out at the site adjacent to the existing Seongdeok Dam for the first time in Korea. The artificial vibrations were induced by 4 different types of blasting with the various depths of blasting boreholes and the various explosive charge weight. During the tests, the accelerations time histories were recorded at the crest of the dam. In this acceleration history, only free vibration decay part following the main vibration event was extracted and it was analyzed by frequency domain analysis using Fast Fourier Transform (FFT). From the results of FFT, the fundamental period of the target dam was evaluated. It is found that the effect of different blasting types on the fundamental period of the target dam is negligible and the fundamental period of the target dam can be consistently obtained by blasting vibration tests. Furthermore, it is found that the period of the target dam calculated by the method using blasting vibration test is similar to that obtained by the method of previous researchers using the real earthquake records. Therefore, in case that the earthquake record is not available, the fundamental period of a rockfill dam can be reasonably evaluated if blasting vibration test is allowed at the site adjacent to the dam.