• Title/Summary/Keyword: ANOVA test

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Application of functional ANOVA and functional MANOVA (단변량 및 다변량 함수 데이터에 대한 분산분석의 활용)

  • Kim, Mijeong
    • The Korean Journal of Applied Statistics
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    • v.35 no.5
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    • pp.579-591
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    • 2022
  • Functional data is collected in various fields. It is often necessary to test whether there are differences among groups of functional data. In this case, it is not appropriate to explain using the point-wise ANOVA method, and we should present not the point-wise result but the integrated result. Various studies on functional data analysis of variance have been proposed, and recently implemented those methods in the package fdANOVA of R. In this paper, I first explain ANOVA and multivariate ANOVA, then I will introduce various methods of analysis of variance for univariate and multivariate functional data recently proposed. I also describe how to use the R package fdANOVA. This package is used to test equality of weekly temperatures in Seoul and Busan through univariate functional data ANOVA, and to test equality of multivariate functional data corresponding to handwritten images using multivariate function data ANOVA.

A Study for Comparing Road Noise by Surface Types using NCPX (NCPX를 이용한 도로 표층 유형별 노면 소음 비교 연구)

  • Kang, Won Pyoung;Moon, Hak Ryong
    • International Journal of Highway Engineering
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    • v.15 no.6
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    • pp.61-68
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    • 2013
  • PURPOSES : The purpose of this study is to study the noise reducing effect of Micro Surfacing by comparing general asphalt, longitudinal tining and Slurry Seal. METHODS : This study measures vehicles' noise of each section by the NCPX method that can measure noise between the road surface and the tire at the field. Total sound pressure and sound pressure level by the 1/3 octave band frequency are calculated through the field data of each section. Total sound pressure level is compared by ANOVA test statistically. After ANOVA test, post-hoc test is conducted to know mean difference of surface type by Tukey. RESULTS : As the result of CPB analysis to confirm sound pressure levels by frequency, it was shown that sound pressure levels by frequency are totally similar except for those of frequency bands between 100Hz and 500Hz. The result of ANOVA test and post-hoc test, it was shown that sections of surface type have a difference. The result of Micro Surfacing was lower 2~5dB(A) than other surface type. CONCLUSIONS : It is found that the noise reduction performance of Micro Surfacing was better than other surface type.

Investigation of the Study Plan and Statistical Method of Functional Cosmetics on Human Skin (기능성 화장품의 인체시험 설계 및 통계적용 방법에 대한 고찰)

  • Seo, Young Kyoung;Koh, Jae Sook;Lee, Won Chul
    • Journal of the Society of Cosmetic Scientists of Korea
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    • v.39 no.2
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    • pp.105-115
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    • 2013
  • In Korea, the human skin tests to evaluate the anti-wrinkles and whitening effect have been accomplished in accordance with the KFDA guideline. Regarding the data of the visual assessment and machinery evaluation of the results for the human skin test, unpaired t-test have been used in order to compare between the test and the control groups and paired t-test for the comparison of effects for before and after. Descriptive statistics such as frequency analyses was used for the questionnaire evaluation data. In many cases of the European and American clinical test centers, the methodology and the statistical analysis were similar to ours. But, the documentation obtained by repeated application from identical individual has high relation. For this reason, it is desirable to apply RM ANCOVA and RM ANOVA to a visual assessment and machinery evaluation. We suggested that RM ANCOVA and RM ANOVA is the new approach to statistical analysis of human test data of functional cosmetics.

The Effect of Glycyrrhizic acid on Vascular Contractility (혈관수축에 대한 감초산 Glycyrrhizic acid의 효과)

  • Hyun Dong Je;Young Sil Min
    • Journal of Industrial Convergence
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    • v.21 no.10
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    • pp.57-63
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    • 2023
  • This study aims to elucidate the effect of glycyrrhizic acid on smooth muscle contraction and to determine the detailed mechanism incorporated. We hypothesized that glycyrrhizic acid played a role in the agonist-sensitive management of smooth muscle contraction. Stripped smooth muscles of Sprague-Dawley rats were prepared in organ baths and isometric tensions were converted, stored and analyzed by using isometric transducers, a physiograph and one way ANOVA. Interestingly, glycyrrhizic acid attenuated the thick filament regulating agonist (fluoride or thromboxane mimetic)-sensitive contraction (p=0.113, 0.008, 0.004 (Student's t-test), p=0.113, 0.008, 0.004 (One way ANOVA) at 0.01, 0.03, 0.1 mM fluoride, and p=0.156, 0.004, 0.003 (Student's t-test), p=0.156, 0.004, 0.003 (One way ANOVA) at 0.01, 0.03, 0.1 mM thromboxane mimetic) and did not attenuate the thin filament regulating agonist (phorbol ester)-induced contraction (p=0.392, 0.086, 0.065 (Student's t-test), p=0.392, 0.086, 0.065 (One way ANOVA) at 0.01, 0.03, 0.1 mM phorbol ester). It is suggesting that endothelial EDRF (NO) synthesis and accessory pathways besides endothelial EDRF (NO) synthesis such as ROCK restriction might be incorporated in the glycyrrhizic acid-induced modulation of smooth muscle contraction inhibiting acto-myosin interaction.

A Study on the Analysis and Identification of Seafarers' Skill-Rule-Knowledge Inherent in Maritime Accidents

  • Yim, Jeong-bin
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.23 no.3
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    • pp.224-230
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    • 2017
  • The purpose of this study is to classify the deficient abilities of seafarers into SRK (Skill, Rule, and Knowledge) and analyze and identify the SRK by the type of accident and ship. Experimental data used the SRK cumulative frequency for 1,606 marine accident records and two-way ANOVA and t-test were used for the analysis tools. The results of two-way ANOVA showed that it is possible to identify the deficient abilities by using the cumulative frequency of SRK in both accident and ship types. As a result of the t-test, the adoption of the null hypothesis (H=0) that the mean of two pairs is equal and the rejection of the null hypothesis (H=1) were 29.2 % and 70.8 %, respectively. For the ship type, H=0 is 33.3 % and H=1 is 66.7 %. Through this study, it was found that about 70 % of the deficient abilities of seafarers inherent in maritime accidents can be identified using the proposed method.

A Study on Order Decision of AR Model for Median Frequency in Fatiguing EMG (근피로 중앙주파수를 위한 AR모델의 차수결정에 관한 연구)

  • Cho, Eun Seuk;Cha, Sam;Lee, Ki Young
    • The Journal of Korea Institute of Information, Electronics, and Communication Technology
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    • v.3 no.1
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    • pp.8-12
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    • 2010
  • In this paper, we studied on AR model order decision for extraction of EMG median frequency by t-test and ANOVA and comparison of median frequency. And we extracted well-known parameters such as zero crossing rate(ZCR), low band energy(Band) and median frequency(MDF) from surface electromyogram (EMG). And we compared to evaluate themselves as measures for fatigue.

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Bioequivalence Test of Biphenyl Dimethyl Dicarboxylate Products (비페닐디메칠디카르복실레이트 제제의 생물학적 동등성 시험)

  • Han, Sang-Soo;Ham, Seong-Ho;Sohn, Dong-Hwan;Kim, Jae-Baek
    • Journal of Pharmaceutical Investigation
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    • v.24 no.2
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    • pp.67-72
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    • 1994
  • Bioequivalence (BE) test of biphenyl dimethyl dicarboxylate (DDB) tablets was performed. Normal healthy male volunteers (n = 20) were randomly divided into 2 groups, and reference $(Nissel{\circledR})$ and test $(Livital{\circledR})$ tablets of DDB $(25mg{\times}8\;Tab.\;= \;200\;mg)$ were given orally by balanced two-period cross-over design. The serum concentration was determined by high performance liquid chromatography. The pharmacokinetic parameters, AUC, $C_{max}$, and $T_{max}$ obtained after drug administration were statistically analyzed. Statistical evaluation of the data involved an analysis of variance (ANOVA) for cross-over design. The results were within 20% differences of mean value in AUC, $C_{max}$, and $T_{max}$ between reference and test tablets. The results of ANOVA showed no significant differences for "between group or subject" and "period". The test tablet was bioequivalent with the reference tablet in the AUC, $C_{max}$, and $T_{max}$.

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Process Optimization of Thermal-sprayed STS316 Coating (STS316 용사코팅의 최적 공정 설계)

  • Kim, Kyun-Tak;Kim, Yeong-Sik
    • Journal of Ocean Engineering and Technology
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    • v.24 no.1
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    • pp.161-165
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    • 2010
  • In the present study, process optimization for thermal-sprayed STS316 coating has been performed using $L_9(3^4)$ orthogonal array and analysis of variance (ANOVA). STS316 coatings were fabricated by flame spray process on steel substrate, and the hardness test and microstructure observation of the coatings were studied. The results of hardness test were analyzed by ANOVA. The ANOVA results showed that the spray distance had the greatest effect on hardness of the coating, on the other hands, the effects of oxygen gas flow and spray distance were ignorable. From these results, the optimal combination of the flame spray parameters could be derived, and confirmation experiment was carried out to verify these derived results. The calculated hardness of the coatings by ANOVA was found to approximately close to that of confirmation experimental result. Thus, it was considered that design of experiments using orthogonal array and ANOVA was effective for process optimization of thermal-sprayed STS316 coating.

Process Optimization for Thermal-sprayed Ni-based Hard Coating by Design of Experiments (실험계획법에 의한 니켈기 경질 용사코팅의 최적 공정 설계)

  • Kim, K.T.;Kim, Y.S.
    • Journal of Power System Engineering
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    • v.13 no.5
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    • pp.89-94
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    • 2009
  • In this work, the optimal process has been designed by $L_9(3^4)$ orthogonal array and analysis of variance(ANOVA) for thermal-sprayed Ni-based hard coating. Ni-based hard coatings were fabricated by flame spray process on steel substrate. Then, the hardness test and observation of microstructure of the coatings were performed. The results of hardness test were analyzed by ANOVA. The ANOVA results demonstrated that the acetylene gas flow had the greatest effect on hardness of the coatings. The oxygen gas flow was found to have a neglecting effect. From these results, the optimal combination of the flame spray parameters could be predicted. The calculated hardness of the coatings by ANOVA was found to lie close to that of confirmation experimental result. Thus, it was considered that design of experiments design using orthogonal array and ANOVA was useful to determine optimal process of thermal-sprayed Ni-based hard coating.

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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.