• Title/Summary/Keyword: Cycle Counting

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Development of HCS(High Contents Screening) Software Using Open Source Library (오픈 소스 라이브러리를 활용한 HCS 소프트웨어 개발)

  • Na, Ye Ji;Ho, Jong Gab;Lee, Sang Joon;Min, Se Dong
    • KIPS Transactions on Software and Data Engineering
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    • v.5 no.6
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    • pp.267-272
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    • 2016
  • Microscope cell image is an important indicator for obtaining the biological information in a bio-informatics fields. Since human observers have been examining the cell image with microscope, a lot of time and high concentration are required to analyze cell images. Furthermore, It is difficult for the human eye to quantify objectively features in cell images. In this study, we developed HCS algorithm for automatic analysis of cell image using an OpenCV library. HCS algorithm contains the cell image preprocessing, cell counting, cell cycle and mitotic index analysis algorithm. We used human cancer cell (MKN-28) obtained by the confocal laser microscope for image analysis. We compare the value of cell counting to imageJ and to a professional observer to evaluate our algorithm performance. The experimental results showed that the average accuracy of our algorithm is 99.7%.

Fatigue Life Evaluation of an Actual Structure under the Irregular Loading using an Acceleration Test (가속시험을 통한 불규칙하중을 받는 실구조물의 피로수명평가)

  • 김형익;배봉국;박재실;석창성;모진용
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2004.10a
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    • pp.166-169
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    • 2004
  • A fatigue test was used to evaluate the fatigue life of an actual structure. The loaded state and the constraint condition of an actual structure must be same as the specimen in order to apply the test results to an actual structure by the specimen. The loaded state and constraint conditions can't be same as the specimen in the actual structure which is complicated. In order to reduce these differences, an actual structure test with a lot of frequencies is need to get a fatigue life curve. Therefore, ten sets of accelerated test units which attached unbalanced mass were composed in this study. Acceleration history about the vibration of an actual structure was acquired. Rainflow counting was used on acceleration history, and the life curve return formula was assumed. The return formula that damage satisfied `1' was acquired in a feedback process by the Miner's rule, which was the linear cumulative damage theory. A conservative fatigue life curve was determined with a return formula to have been presumed by each set. The fatigue life of regular rpm condition was calculated by these conservative fatigue life curves.

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Fatigue Cumulative Damage and Life Prediction of Freight Bogie using Rainflow Counting Method under Service Loading (운전하중하의 레인플로집계법을 이용한 화차 대차의 피로누적손상과 수명예측)

  • Jeon, Joo-Heon;Baek, Seok-Heum;Lee, Kyoung-Young;Cho, Seok-Swoo;Joo, Won-Sik
    • Proceedings of the KSME Conference
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    • 2004.04a
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    • pp.114-119
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    • 2004
  • Endbeam is an important structural member of freight bogie for the support of service loading. In general, more than 25 years' durability is necessary. However, endbeam occur fatigue fracture in dynamic stress concentration location because comparatively strength and stiffness are low. Therefore, structure analysis is performed to evaluate structural problem of endbeam and local strain range as durability analysis. The number of cycles is extracted concerning the bogie in operation by measurement dynamic stress time history on critical part which is crack initiation in actual fact. At this time rainflow cycle counting is used to consider change of stress for operating condition. Based on the fatigue life curves and the stress analysis, the fatigue life of the endbeam is predicted and compared with the experimentally determined fatigue life, resulting in a fairly good correlation.

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S-N Curve Estimation of a KTX Structure for an Accelerated Life Testing (가속수명시험을 위한 KTX 구조물의 S-N 선도 추정)

  • Jung, Dal-Woo;Choi, Nak-Sam;Park, Su-Han
    • Proceedings of the KSME Conference
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    • 2008.11a
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    • pp.384-389
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    • 2008
  • An accelerated fatigue test is essentially required to maintain the reliability of the actual structure of KTX under operation conditions. However, actual fatigue life cannot be obtained if specimens are not adequate to the conventional fatigue test. Moreover component maker did not provide data of loading stress (S) - cycles at the failure (N). In this study, we suggest a prediction method of the S-N curve for establishing an accelerating test under various load levels. Load history was acquired from the field tests. A Rainflow method was used on the cycle counting of the field load data, and then, an S-N curve was obtained through the iteration process under the condition that the damage index satisfies to 1 in the Miner's rule.

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A Study on Computational Method for Fatigue Life Prediction of Vehicle Structures (차체 구조물의 피로수명 예측을 위한 컴퓨터 시뮬레이션 방법에 관한 연구)

  • 이상범;박태원;임홍재
    • Journal of KSNVE
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    • v.10 no.4
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    • pp.686-691
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    • 2000
  • In this paper a computer aided analysis method is proposed for durability assessment in the early design stages using dynamic analysis, stress analysis and fatigue life prediction method. From dynamic analysis of a vehicle suspension system, dynamic load time histories of a suspension component are calculated. From the dynamic load time histories and the stress of the suspension component, a dynamic stress time history at the critical location is produced using the superposition principle. Using linear damage law and cycle counting method, fatigue life cycle is calculated. The predicted fatigue life cycle is verified by experimental durability tests.

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A Study on Computational Method for Fatigue Life Prediction of Vehicle Structures (차체 구조물의 피로수명 예측을 위한 컴퓨터 시뮬레이션 방법에 관한 연구)

  • Lee, Sang-Beom;Park, Tae-Won;Park, Jong-Sung;Lee, Sun-Byung;Yim, Hong-Jae
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2000.06a
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    • pp.1883-1888
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    • 2000
  • In this paper a computer aided analysis method is proposed for durability assessment in the early design stages using dynamic analysis, stress analysis and fatigue life prediction method. From dynamic analysis of a vehicle suspension system, dynamic load time histories of a suspension component are calculated. From the dynamic load time histories and the stress of the suspension component, a dynamic stress time history at the critical location is produced using the superposition principle. Using linear damage law and cycle counting method, fatigue life cycle is calculated. The predicted fatigue life cycle is verified by experimental durability tests.

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The Effects of Loranthus parasiticus Merr. on Cell Cycle and Expression of Related Genes in HepG2 Cell (상기생(桑寄生)이 HepG2 cell의 세포분열 및 관련유전자 발현에 미치는 영향)

  • Rhew, Kwang-Yul;Kim, Young-Chul;Woo, Hong-Jung;Lee, Jang-Hoon
    • The Journal of Internal Korean Medicine
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    • v.26 no.1
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    • pp.60-73
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    • 2005
  • Objectives : The aim of this study was to evaluate the effects of Loranthus parasiticus Merr. on cell cycle and expression of related genes in HepG2 cells. Methods : The MTT assay, cell counting assay, $[^3H]-Thymidine$ incorporation assay, flow cytometric analysis, quantitative RT-PCR and western blot assay were studied. Results : In the water extract of Loranthus parasiticus Merr., inhibition of cell proliferation and DNA synthesis in HepG2 cells was seen. These inhibitory effects were due to inhibition of G l-S transition in cell cycle. After treatment with the extract, expression of cyclin D1(G1 check point related gene) was inhibited particularly in dose-dependent and time-dependent manners. Conclusion : These results suggest that the inhibition of cell cycle progression by Loranthus parasiticus Merr. in HepG2 cell is due to suppression of cyclin D1(G1 check point related gene) mRNA expression and protein synthesis.

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Active Days around Solar Minimum and Solar Cycle Parameter

  • Chang, Heon-Young
    • Journal of Astronomy and Space Sciences
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    • v.38 no.1
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    • pp.23-29
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    • 2021
  • Utilizing a new version of the sunspot number and group sunspot number dataset available since 2015, we have statistically studied the relationship between solar activity parameters describing solar cycles and the slope of the linear relationship between the monthly sunspot numbers and the monthly number of active days in percentage (AD). As an effort of evaluating possibilities in use of the number of active days to predict solar activity, it is worthwhile to revisit and extend the analysis performed earlier. In calculating the Pearson's linear correlation coefficient r, the Spearman's rank-order correlation coefficient rs, and the Kendall's τ coefficient with the rejection probability, we have calculated the slope for a given solar cycle in three different ways, namely, by counting the spotless day that occurred during the ascending phase and the descending phase of the solar cycle separately, and during the period corresponding to solar minimum ± 2 years as well. We have found that the maximum solar sunspot number of a given solar cycle and the duration of the ascending phase are hardly correlated with the slope of a linear function of the monthly sunspot numbers and AD. On the other hand, the duration of a solar cycle is found to be marginally correlated with the slope with the rejection probabilities less than a couple of percent. We have also attempted to compare the relation of the monthly sunspot numbers with AD for the even and odd solar cycles. It is inconclusive, however, that the slopes of the linear relationship between the monthly group numbers and AD are subject to the even and odd solar cycles.

Application of Accelerated Vibration Testing to Spot-welding Specimen (점용접 표준시편에 대한 가속내구시험법의 적용)

  • 김관주;조성신;정진성
    • Transactions of the Korean Society of Automotive Engineers
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    • v.11 no.3
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    • pp.209-213
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    • 2003
  • It is advantage of accelerated vibration testing to compress service exposures to operating vibration into a reduced laboratory test by increasing the amplitude or frequency of the applied input excitations. This paper proposes an accelerated test method to estimate the high-cycle fatigue life under random excitation. The method consists of conducting a test with amplified input excitation and extrapolating linearly the lift in the accelerated condition into the real lift in field condition. The extrapolation is carried out applying the high-cycle irregular excitation fatigue theory including the rainflow counting, Miner’s damage accumulation rule, and Goodman’s mean stress correction. As a verification, those estimated lift is compared with that acquired by experiment f3r the simple case of spot welding specimen with good agreement. This testing procedure will provide an useful scheme that can reduce testing period associated with developing time schedule of new product.