• Title/Summary/Keyword: Variance Analysis of Variance(ANOVA)

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Statistical Analysis of a Loop Designed Microarray Experiment Data (되돌림설계를 이용한 마이크로어레이 실험 자료의 분석)

  • 이선호
    • The Korean Journal of Applied Statistics
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    • v.17 no.3
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    • pp.419-430
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    • 2004
  • Since cDNA microarray experiments can monitor expression levels for thousands of genes simultaneously, the experimental designs and their analyzing methods are very important for successful analysis of microarray data. The loop design is discussed for selecting differentially expressed genes among several treatments and the analysis of variance method is introduced to normalize microarray data and provide estimates of the interesting quantities. MA-ANOVA is used to illustrate this method on a recently collected loop designed microarray data at Cancer Metastasis Research Center, Yonsei University.

Evaluating the Effect of Specimen Thickness on Fatigue Crack Growth in AZ31 Alloy Using ANOVA (분산분석법을 이용한 AZ31 합금의 피로균열성장에 미치는 시편두께 효과 평가)

  • Choi, Seon Soon
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.19 no.6
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    • pp.9-16
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    • 2020
  • This study aims to assess the effects of specimen thickness (ST) on fatigue crack growth in the early stages of crack propagation and near failure in magnesium alloys. The analysis of variance (ANOVA) method was adopted because fatigue crack propagation in magnesium alloys exhibits statistical behavior. The equality of variance test and residual diagnostics were performed on the grown cracks to confirm the validity of ANOVA by verifying the normal distribution and mutual independence of the residuals and their homoscedasticity. ANOVA confirmed that ST heavily impacts crack growth; i.e., when ST is smaller, cracks grow faster in the early crack propagation stage and break more quickly before the formation of larger cracks. We found that ST significantly affects fatigue crack growth in the early crack propagation stage and near the failure stage in magnesium alloys. The regression model was also used to predict crack formation near the failure stage.

Hierarchical Bayes Estimators of the Error Variance in Balanced Fixed-Effects Two-Way ANOVA Models

  • Kim, Byung-Hwee;Dong, Kyung-Hwa
    • Communications for Statistical Applications and Methods
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    • v.6 no.2
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    • pp.487-500
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    • 1999
  • We propose a class of hierarchical Bayes estimators of the error variance under the relative squared error loss in balanced fixed-effects two-way analysis of variance models. Also we provide analytic expressions for the risk improvement of the hierarchical Bayes estimators over multiples of the error sum of squares. Using these expressions we identify a subclass of the hierarchical Bayes estimators each member of which dominates the best multiple of the error sum of squares which is known to be minimax. Numerical values of the percentage risk improvement are given in some special cases.

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Study on the Result Changes with the Size of the Variance in Taguchi Method and Factor Experimental (다구찌 기법과 요인실험의 실험 데이터의 산포 크기에 따라 결과 변화 고찰)

  • Ree, Sangbok
    • Journal of Korean Society for Quality Management
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    • v.41 no.1
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    • pp.119-134
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    • 2013
  • Purpose: The purpose of this paper is to show whether the results are changed with respect to the variance of the data, by analysis of data obtained from the Taguchi experimental techniques and general experiment. Because which cannot be prove by mathematical Formula, through experimental examples will show. Methods: Taguchi experiments were carried out with paper Helicopter experiment. Experimental Data are obtained by special designed Drop Test Equipment. While Experimental value arbitrarily changed, we looked at how Significant control Factor of Taguchi Methods and Factor experiments are changed. This process cannot be expressed as a Mathematical formula, but showed as a numerical example. Results: Saw significant changes in the factors when data is outside a certain range of the experimental data. By Test of Equivalence Variance, Experiment data is verified reliability. To find the Control Factor, Taguchi Method is better than the general experiment. Conclusion: We know that a Significant Factor is changed with the range of Variance of Experiment Data. The value of this paper is verified change process with Numerical Data obtained Experiment.

Pooling Variance Tests Using Expected Mean Square in Split-Plot Designs (분할법에서 EMS알고리즘을 이용한 풀링분산검정)

  • Choi, Sung-Woon
    • Journal of the Korea Safety Management & Science
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    • v.10 no.3
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    • pp.245-251
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    • 2008
  • The research proposes three ANOVA(Analysis of Variance) tests using expected mean square(EMS) algorithms in various split-plot designs. The variance tests consist of Never-Pool test, Sometimes-Pool test and Always-Pool test. This paper also presents two EMS algorithms such as standard method and easy method. These algorithms are useful to make a decision rule for pooling. Numerical examples are illustrated for various split-plot designs such as split-plot designs, split-split-plot designs, repetition split-plot designs, and nested designs. Pragmatically, the results are summarized and compared with popular ANOVA spreadsheets and data model equations.

Surface roughness evaluation in turning by an orthogonal array method (직교배열법에 의한 선삭가공시 표면거칠기 평가)

  • 배병중;박태준;양승한;이영문;김희술
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2000.11a
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    • pp.862-865
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    • 2000
  • The object of this paper is to evaluate the surface roughness using the experimental equation of surface roughness, which is developed in turning by an orthogonal array method. $L_9{3^4}$ orthogonal array method, one of fractional factorial design has been used to study effects of main cutting parameters such as cutting speed, feed rate and depth of cut, on the surface roughness. And the analysis of variance (ANOVA)-test has been used to check the significance of cutting parameters. Using the result of ANOVA-test, the experimental equation of surface roughness, which consists of only significant cutting parameter - feed rate, has been developed. The coefficient of determination of this equation is 0.962.

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Process Optimization for Co-based Self-flux Alloy Coating by Taguchi Method (다구찌 기법에 의한 코발트기 자융성합금 용사코팅의 최적공정 설계)

  • Lee, Jae-Hong;Kim, Yeong-Sik
    • Journal of Power System Engineering
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    • v.17 no.6
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    • pp.108-114
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    • 2013
  • This paper describes process optimization for thermal-sprayed Co-based self-flux alloy coating by Taguchi method. Co-based self-flux alloy coatings were fabricated according to $L_9(3^4)$ orthogonal array using flame spray process. Hardness test and wear test were performed, the results were analyzed by analysis of variance(ANOVA) considering a multi response signal to noise ratio(MRSN). From the results of ANOVA, the optimal combination of the flame spray parameters on Co-based self-flux alloy coating could be predicted. The calculated hardness and wear rate of the coatings by ANOVA were found to be close to that of confirmation experimental result.

Morphological Analysis among Populations of Purpulish Washington Clam, Saxidomus purpuratus on the Korean Waters

  • Kim, Yeong-Hye;Ryu, Dong-Ki;Lee, Dong-Woo;Chang, Dae-Soo;Kim, Jong-Bin;Kim, Seong-Tae;Kwon, Dae-Hyeon
    • The Korean Journal of Malacology
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    • v.22 no.1 s.35
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    • pp.23-26
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    • 2006
  • Morphological differences were studied using the analysis of variance between various partial length and shell length of three populations of Saxidomus purpuratus on the Korean waters. The Relative growth equations, that is, SH-SL, SW-SL, TW-SL of S. purpuratus by sex were estimated. The analysis of variance of four morphological characters proved that each population has no sexual differences (p>0.01). But the three populations are significantly different in morphological characters (p<0.01).

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Optimal Design of Ferromagnetic Pole Pieces for Transmission Torque Ripple Reduction in a Magnetic-Geared Machine

  • Kim, Sung-Jin;Park, Eui-Jong;Kim, Yong-Jae
    • Journal of Electrical Engineering and Technology
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    • v.11 no.6
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    • pp.1628-1633
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    • 2016
  • This paper derives an effective shape of the ferromagnetic pole pieces (low-speed rotor) for the reduction of transmission torque ripple in a magnetic-geared machine based on a Box-Behnken design (BBD). In particular, using a non-linear finite element method (FEM) based on 2-D numerical analysis, we conduct a numerical investigation and analysis between independent variables (selected by the BBD) and reaction variables. In addition, we derive a regression equation for reaction variables according to the independent variables by using multiple regression analysis and analysis of variance (ANOVA). We assess the validity of the optimized design by comparing characteristics of the optimized model derived from a response surface analysis and an initial model.

An Empirical Study on the Impact of Job Performance to AIS Utility Value (회계정보시스템 유용성이 업무성과에 미치는 영향에 관한 실증적 연구)

  • Kim Dong-Il
    • The Journal of the Korea Contents Association
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    • v.5 no.5
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    • pp.266-272
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    • 2005
  • This study is to empirically analyze the effects on job performance of Accounting Information Systems, Analysis methods were used to Cronbach's Alpha analysis, Factor analysis, analysis of variance(ANOVA) and regression in odor by the contingency grouping method. The results of this study are as follows : First, The regression analysis had effects on AIS utility and job performance. Second, The Analysis of variance(ANOVA) had non-effects on systems operating degree and systems satisfaction. Third, The input variables of information accuracy and systems satisfaction had additional effect about IT capability.

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