• Title/Summary/Keyword: Life variation

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The Base Sequence of ITS and Genetic Variation in Sarcodon Aspratus (능이버섯의 ITS염기서열과 유전적 변이)

  • Kim Jong Bong
    • Journal of Life Science
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    • v.14 no.6 s.67
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    • pp.963-966
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    • 2004
  • The sequence of ITS (partial 16S ribosomal DNA, complete ITS1, 5.8S ribosomal DNA and ITS2, and partial 28S ribosomal DNA) was analysed by PCR and autosequencing in Sarcodon aspratus. The ITS lenght of S. aspratus was 716 base pair. As this sequence compared with other reports on S. aspratus (ace No AF335110), the sequence variation based on nucleotide deletion and substitution was $1.8\%$. This nucleotide variation rate in same species was very higher than in other species. Also, the sequence varitation rates between this S. aspratus and S. imbricatus, and S. squamus were $8\%\;and\;10\%$, respectively. This results suggested that the high sequence variation of S. aspratus might be caused specific host and inhabitat environment which limited gene flow.

A Stochastic Analysis of Variation in Fatigue Crack Growth of 7075-T6 Al alloy (7075-T6 A1 합금의 피로균열진전의 변동성에 대한 확률론적 해석)

  • Kim, Jung-Kyu;Shim, Dong-Suk
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.20 no.7
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    • pp.2159-2166
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    • 1996
  • The stochastic properties of variation in fatigue crack growth are important in reliability and stability of structures. In this study,the stochastic model for the variation of fatigue crack growth rate was proposed in consideration of nonhomogeneity of materials. For this model, experiments were ocnducted on 7075-T6 aluminum alloy under the constant stress intensity factor range. The variation of fatigue crack growth rate was expressed by random variables Z and r based on the variation of material coefficients C and m in the paris-Erodogan's equation. The distribution of fatigue life with respect to the stress intensity factor range was evaluated by the stochastic Markov chain model based on the Paris-Erdogan's equation. The merit of proposed model is that only a small number of test are required to determine this this function, and fatigue crack growth life is easily predicted at the given stress intensity factor range.

Variation in Significant Difference of Sausage Textural Parameters Measured by Texture Profile Analysis (TPA) under Changing Measurement Conditions

  • Shin, Sun-Hwa;Choi, Won-Seok
    • Food Science of Animal Resources
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    • v.41 no.4
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    • pp.739-747
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    • 2021
  • This study examined the measurement conditions of the texture profile analysis (TPA) experiments that are typically used to measure the physical properties of sausage. As the measurement conditions (compression ratio and cross-head speed) were changed, the significant differences between the values of textural parameters (hardness, adhesiveness, springiness, cohesiveness, chewiness) of samples changed. Furthermore, among the measurement conditions, there was more variation in the significant difference between the value of samples due to a change in the compression ratio than due to a change in the cross-head speed. The highest variation in significant difference was observed between the values of cohesiveness of samples due to changes in measurement conditions, whereas the lowest variation in significant difference was observed between the values of springiness of samples due to change in measurement conditions. Therefore, it is desirable to provide a clear basis for setting specific measurement conditions for TPA test, since significant differences in the values of textural parameters of samples were caused by differences in cross-head speed or compression ratio, not by a difference in samples, when analyzing the cohesiveness of sausage, especially.

Technique to reinforce the structure using the sensitivity information (민감도 정보를 이용한 구조물의 내구보강 기법)

  • Kwon, Sung-Hun;Yoo, Hong-Hee
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2008.11a
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    • pp.474-478
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    • 2008
  • In this paper, the technique to reinforce the structure using the sensitivity information is proposed. Design variables related to the geometry of structure at fatigue fracture points are determined and sensitivities of fatigue life at fracture points with respect to the variation of design variables are calculated. Then the vector composed of gaps between the target life and initial life cycles at fracture points is calculated. The linear algebraic equation to solve the variation of design variables is composed. From the equation, the design variables for reinforced structure are determined.

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Comparative Morphology and Seasonality of Campylaephora borealis and C. crassa (Ceramiaceae, Rhodophyta)

  • Seo, Kyung-Suk;Boo, Sung-Min
    • ALGAE
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    • v.20 no.4
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    • pp.325-331
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    • 2005
  • Populations of Campylaephora borealis (Nakamura) Seo, Cho et Boo and C. crassa (Okamura) Nakamura show a year-around occurrence of all life-history stages. Such a concurrency of life-history stages produces problems in recognizing species in the field. Here, we invesitgated the morphological variation and life-history stages of both species using a statistical character analysis. Life-history stage was correlated with the seawater temperature in C. borealis, whereas it was dependant on biomass in C. crassa. Thalli had dichotomous branches with adaxial branchlets. The statistics showed that the seasonal change in morphology of C. borealis was significantly different from that of C. crassa in seven qualitative characters and five quantitative characters (p < 0.001), although six quantitative features including tetrasporangial size were similar in both species. The morphological difference between the two species may be due to the annual variation of branchlet number and the variance of branch subangle.

Design of ALT Control Chart for Small Process Variation (미세변동공정관리를 위한 가속수명시험관리도 설계)

  • Kim, Jong-Gurl;Um, Sang-Joon
    • Journal of the Korea Safety Management & Science
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    • v.14 no.3
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    • pp.167-174
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    • 2012
  • In the manufacturing process the most widely used $\bar{X}$ chart has been applied to control the process mean. Also, Accelerated Life Test(ALT) is commonly used for efficient assurance of product life in development phases, which can be applied in production reliability acceptance test. When life data has lognormal distribution, through censored ALT design so that censored ALT data has asymptotic normal distribution, $ALT\bar{X}$ control chart integrating $\bar{X}$ chart and ALT procedure could be applied to control the mean of process in the manufacturing process. In the situation that process variation is controlled, $Z_p$ control chart is an effective method for the very small fraction nonconforming of quality characteristic. A simultaneous control scheme with $ALT\bar{X}$ control chart and $Z_p$ control chart is designed for the very small fraction nonconforming of product lifetime.

Adsorption of Ammonia on Municipal Solid Waste Incinerator Bottom Ash Under the Landfill Circumstance

  • Yao, Jun;Kong, Qingna;Zhu, Huayue;Zhang, Zhen;Long, Yuyang;Shen, Dongsheng
    • Korean Chemical Engineering Research
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    • v.53 no.4
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    • pp.503-508
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    • 2015
  • The adsorption characteristics of ammonia on MSWI bottom ash were investigated. The effect of the variation of the landfill environmental parameters including pH, anions and organic matter on the adsorption process was discussed. Results showed that the adsorption could be well described by pseudo-second-order kinetics and Langmuir model, with a maximum adsorption capacity of 156.2 mg/g. The optimum adsorption of ammonia was observed when the pH was 6.0. High level of ion and organic matter could restrict the adsorption to a low level. The above results suggested that MSWI bottom ash could affect the migration of ammonia in the landfill, which is related to the variation of the landfill circumstance.