• Title/Summary/Keyword: Decay time

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Comparison of the change in quality indices during distribution period by import season in three grape cultivars

  • Kim, Sung-Joo;Noh, Soo-In;Lim, Byung-Sun;Chun, Jong-Pil
    • Korean Journal of Agricultural Science
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    • v.46 no.1
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    • pp.45-56
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    • 2019
  • As a result of analyzing the quality of imported grapes during the 2018 season, the hardness of the grape berry was found to be 10 N or less in total. In the case of Chilean grapes, the soluble solids tended to be lower as imports and distribution periods were delayed. The berry weight was the largest at 14.4 - 14.8 g for the 'Red Globe', 7.1 - 7.4 g for the 'Thompson Seedless' and 6.0 - 7.0 g for the 'Crimson Seedless'. The 'Crimson Seedless' grapes imported from Chile, which had a high berry shatter rate, had a shorter pedicel length, pad width and brush length than that of the other 2 varieties. Regardless of the grape varieties, the weight loss during the distribution at room temperature ($25^{\circ}C$) increased rapidly as the import season was delayed. Additionally, it was found that the later the distribution seasons, a higher stem browning index was observed regardless of the variety. The 'Thompson Seedless' was revealed to be more susceptible to browning than that of the other varieties. The shrinkage of the stem and the pedicel browning progressed within a short time during shelf-life as the distribution time was delayed. The incidence of berry decay of the imported grapes tended to increase with the progression of the distribution period. In the fruits distributed on April, except for the 'Crimson Seedless', the grapes were rapidly corrupted in the second half of the distribution. The 'Red Globe' grapes completely lost marketability due to a berry decay of 26.1% and 69.9% at 9 and 12 days after shelf-life, respectively.

A Method for Determining Dead Times of a G.M. Defector as a Function of the Count Rate

  • Ro, Seung-Gy
    • Nuclear Engineering and Technology
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    • v.3 no.1
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    • pp.3-7
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    • 1971
  • A method for determining dead times of a G.M. detector as a function of the count rate has been investigated using the Mn$^{56}$ radioactive sample. The formula, (equation omitted), seems to be useful for determining a relation between the dead time and the count rate. Here (equation omitted)(N$_1$) is the dead time for the count rate N$_1$, N$_1$is the count rate at time zero, Nt is the count rate at time t, λ is the radioactive decay constant of the sample used, and t is the time between the first and second runs. When all the counting data were corrected for the dead times evaluated with this formula and then a variation of these corrected counting data with rime was observed, the results showed quite a good agreement with the published data for the radioactive decay of Mn$^{56}$ . Besides, it appears that the dead time decreases as the count rate increases in a dead time-to-count rate relation obtained by the same formula.

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STATIONARY $\beta-MIXING$ FOR SUBDIAGONAL BILINEAR TIME SERIES

  • Lee Oe-Sook
    • Journal of the Korean Statistical Society
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    • v.35 no.1
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    • pp.79-90
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    • 2006
  • We consider the subdiagonal bilinear model and ARMA model with subdiagonal bilinear errors. Sufficient conditions for geometric ergodicity of associated Markov chains are derived by using results on generalized random coefficient autoregressive models and then strict stationarity and ,a-mixing property with exponential decay rates for given processes are obtained.

Time variation characteristic of pulse-modulated high frequency plasma (펄스 모듈레이션된 고주파 플라즈마의 시변 특성)

  • Lee, S.H.;Lee, D.S.;Jo, Y.S.;Kim, D.H.;Lee, H.J.;Park, C.H.
    • Proceedings of the KIEE Conference
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    • 2004.07c
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    • pp.1817-1819
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    • 2004
  • From the plasma application point of view, electron temperature and density are one of the most important parameters for plasma process. But it is only available to control plasma by adjusting external factors like gas pressure and input power. In this paper, pulse-modulated plasma is generated by modulating 13.56GHz RF power with 1, 5, 10kHz pulse. And Langmuir probe technique is used to study the distribution of electron temperature and density. When modulated pulse is off, electron temperature decreases gradually in form of exponential decay. The value t of exponential decay slope is 33.619, 13.834, 10.803 in 1kHz. 5kHz. 10kHz. This implies that this method can be used to control electron temperature and density.

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Thermal and Non-thermal Heat Flow in a Large Crystal Detector for Neutrinoless Double Beta Decay Search

  • Kim, G.B.;Lee, S.J.;Jang, Y.S.;Lee, H.J.;Lee, J.H.;Lee, J.Y.;Lee, M.K.;Yoon, W.S.;Kim, Y.H.
    • Progress in Superconductivity
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    • v.14 no.2
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    • pp.87-91
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    • 2012
  • Metallic magnetic calorimeters (MMCs) are one of the most competitive low temperature detector (LTD) readout sensors. They have the advantages of high time resolution, no heat dissipation, and a wide range of operating temperature. We apply MMCs to our neutrinoless double beta decay ($0v{\beta}{\beta}$) search experiment. A $CaMoO_4$ crystal was employed as both a source of $0v{\beta}{\beta}$ and an energy absorber. The crystal was thermally connected to a MMC sensor. We set a simple thermal model for this detector and measured pulse shapes are compared with a numerical solution of the thermal model.

The decay phenomenon of II-VI compound semiconductors (II-VI 화합반도체소자의 열화현상)

  • Young Kwon Sung
    • 전기의세계
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    • v.17 no.2
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    • pp.16-26
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    • 1968
  • Cds is possible to add excess donors and to compensate partially using other group metals as acceptors. The impurities can ble incorporated either during crysta growth or by diffusion into a bulkcrystal. The addition of rimpurities leads also to the production of vacancies in a manner depending on the atmosphere surrounding the crystal during growth, during the diffusion process or using bulk. Cds of the mentioned above affects spectral sensitivity, speed of response, the variation on photocurrent, electron life time, and decay of photoconductivity with temperature and with intensity of illumination. In the work to be deseribed, these properties have been studied between liquid nitrogen and room temperature. In addition, the electron trap distribution has been correlated with speed of response, variation of photocurrent with temperature in various atmosphere. Four major trapping levels have been observed, and their identification with impurity and vacancy levels is discussed. And also the effects of lattice imperfections on the photoconductive properties CdS were investigated in detail.

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Manufacture and Properties of Gypsum-Wood (Gypsum-Wood의 제조와 성질)

  • Lee, Jong-Shin;Kim, Soung-Joon
    • Journal of the Korea Furniture Society
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    • v.19 no.1
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    • pp.83-90
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    • 2008
  • Gypsum-wood composites were made by introducing inorganic substances into wood using calcium chloride, first treating solution, and sodium sulfate, secondary treating solution, by double diffusion process under atmospheric pressure at room temperature. The process conducted as follows: water saturated specimens were soaked in calcium chloride solutions at several concentration. Then the specimens were soaked further in saturated sodium sulfate solution, and they were leached in flowing tap water for 24h. To attain sufficient weight percent gain (WPG) values, the suitable concentration of calcium chloride and soaking time in saturated sodium sulfate solution were 20% and 48h, respectively. Inorganic substances were produced mainly in the lumina of tracheides. It was made sure that these substances were dihydrate gypsum($CaSO_4$ $2H_2O$) by X -ray microanalysis (SEM-EDX). The composites had good fire resistance due to low heat transfer rate of gypsum formed in wood. However, the composites had little decay resistances, because they showed high weight losses by test fungi attacks.

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Time Domain Identification of Structures Using Test Data (측정자료를 이용한 시간영역에서의 구조물의 동특성 추정)

  • 한종석;정범석
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 1996.10a
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    • pp.159-167
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    • 1996
  • This paper describes the theory and verification of a method which utilizes the free decay response of a structure to determine its vibration parameters. The theory of the method is base on the formulation of a system matrix, contains information characterizing the complete set of modal parameters of the system, and its eigen-solution problem. The applicability of the method is verified by simulated free decay response data of a cantilever bean The method described was used to determined the parameters related to the first five generated modes of vibration of a cantilever beam. It involves two very close natural frequencies which could not be identified using a frequency sweep test(peak amplitude) because of interference between modes.

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