• Title/Summary/Keyword: Variance of Analysis

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The effect of powder A2/powder A3 mixing ratio on color and translucency parameters of dental porcelain

  • Lee, Wan-Sun;Kim, So-Yeon;Kim, Ji-Hwan;Kim, Woong-Chul;Kim, Hae-Young
    • The Journal of Advanced Prosthodontics
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    • v.7 no.5
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    • pp.400-405
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    • 2015
  • PURPOSE. The purpose of this study is to mix dental ceramic powder in varying ratios and evaluate the effect of the mixing ratio on color and translucency. MATERIALS AND METHODS. The ceramic powder of shade A3 of the same product was mixed with the shade A2 of three products: IPS e.max Ceram (Ivoclar Vivadent, Schaan, Liechtenstein), Vintage Halo (SHOFU Inc., Kyoto, Japan), and Ceramco 3 (Ceramco-Dentsply, Burlington, NJ, USA) in the following fixed ratios (0 wt%, 25 wt%, 50 wt%, 75 wt%, and 100 wt%) and then fired. A total of 150 specimen of ceramic fired were manufactured in a regular size (W: 8.5 mm, L: 10.5 mm, and H: 1.5 mm). For color and translucency, $L^*$, $a^*$, and $b^*$ were measured and Two-way analysis of variance (ANOVA) and One-way analysis of variance (ANOVA) were used for data analysis (${\alpha}$=0.05). RESULTS. The higher the mixing ratio was, $L^*$, $a^*$, and $b^*$ of IPS e.max Ceram were all increased, and $L^*$ of Vintage Halo was reduced and $a^*$ and $b^*$ were increased. $L^*$ and $a^*$ of Ceramco3 were reduced and $b^*$ of Ceramco3 was increased. Color difference (${\Delta}E^*ab$) was increased in all three products as the mixing ratio got higher. Increased mixing ratios resulted in decreased translucency parameter (TP) values for IPS e.max Ceram but increased TP values for Vintage Halo and Ceramco3. CONCLUSION. In this limited study, CIE $L^*$, $a^*$, and $b^*$ were influenced by the mixing ratio of the A3 powders and porcelain powder mixtures represented a various color and translucency.

A Study on In-line Skate Clothing Interest of In-line Skaters (인라인스케이터의 인라인스케이트 의복흥미 연구(Ⅱ))

  • Jung, Tae-Jin;Yoo, Tai-Soon
    • Fashion & Textile Research Journal
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    • v.6 no.6
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    • pp.731-739
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    • 2004
  • As the life styles have been changed in modern society and sports gave been emphasized for spending spare time and improving health condition, sports are regarded to lave a leading role to fashion as one of the prominent factors. This study is to analyze the gender-identity and how different levels of involvement in In-line skating affects clothing interests. 291 In-line skaters ranged in age from middle twenties to middle thirties were surveyed and measured for this study. MANOVA(multivariate analysis of variance), ANOVA(univariate analysis of variance), Cronbach ${\alpha}$ reliability, t-test, and correlation analysis were performed with SPSS 10.0 program on the selected data. The results of this study are as follow. There were no obvious differences in In-line skating clothing interests by gender of In-line skaters. There were, however, differences in the reasons for In-line skating, the hours to skate per week. Those whose purpose for skating was diet had more interest in style focused on expression. In case of skating for health, they showed interest in activity-functionality style and anti-deviation style. The group of In-line skaters who skated 15 to 18 per week gave more interest in activity-functionality style out of the clothing interest-factors. Those who had strong masculinity in gender-identity of In-line skaters were more involved in In-line skating. There were some differences in clothing interests according to gender-identity of In-line skaters. In regard of In-line skating clothing interest by involvement in In-line skating, those who had higher involvement in In-line skating had higher In-line skating clothing interest.

Re-evaluation of Obesity Syndrome Differentiation Questionnaire Based on Real-world Survey Data Using Data Mining (데이터 마이닝을 이용한 한의비만변증 설문지 재평가: 실제 임상에서 수집한 설문응답 기반으로)

  • Oh, Jihong;Wang, Jing-Hua;Choi, Sun-Mi;Kim, Hojun
    • Journal of Korean Medicine for Obesity Research
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    • v.21 no.2
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    • pp.80-94
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    • 2021
  • Objectives: The purpose of this study is to re-evaluate the importance of questions of obesity syndrome differentiation (OSD) questionnaire based on real-world survey and to explore the possibility of simplifying OSD types. Methods: The OSD frequency was identified, and variance threshold feature selection was performed to filter the questions. Filtered questions were clustered by K-means clustering and hierarchical clustering. After principal component analysis (PCA), the distribution patterns of the subjects were identified and the differences in the syndrome distribution were compared. Results: The frequency of OSD in spleen deficiency, phlegm (PH), and blood stasis (BS) was lower than in food retention (FR), liver qi stagnation (LS), and yang deficiency. We excluded 13 questions with low variance, 7 of which were related to BS. Filtered questions were clustered into 3 groups by K-means clustering; Cluster 1 (17 questions) mainly related to PH, BS syndromes; Cluster 2 (11 questions) related to swelling, and indigestion; Cluster 3 (11 questions) related to overeating or emotional symptoms. After PCA, significant different patterns of subjects were observed in the FR, LS, and other obesity syndromes. The questions that mainly affect the FR distribution were digestive symptoms. And emotional symptoms mainly affect the distribution of LS subjects. And other obesity syndrome was partially affected by both digestive and emotional symptoms, and also affected by symptoms related to poor circulation. Conclusions: In-depth data mining analysis identified relatively low importance questions and the potential to simplify OSD types.

Factors influencing infertility-related quality of life in infertile women (난임 여성의 난임관련 삶의 질 영향요인)

  • Kim, Yun Mi;Nho, Ju-Hee
    • Women's Health Nursing
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    • v.26 no.1
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    • pp.49-60
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    • 2020
  • Purpose: Infertile women experience various physical, psychological, and relational problems that affect their infertility-related quality of life (QoL). This study investigated infertile women's infertility-related QoL with the goal of identifying how it is influenced by fatigue, depression, and marital intimacy. Methods: A sample of 140 infertile women was surveyed in a cross-sectional study. Data were collected from February to April 2018 using self-report structured questionnaires at three infertility clinics located in Jeonju, Korea. Data were analyzed using the independent t-test, analysis of variance, Pearson correlation coefficients, and stepwise multiple regression analysis in SPSS for Windows version 25.0. The subjects agreed to complete a face-to-face interview, including administration of the Fatigue Severity Scale, Depression Anxiety Stress Scale-21, Marital Intimacy Scale, and the Fertility Quality of Life tool. Results: The mean age of the participants was 35.6±4.3 years. Infertility-related QoL was negatively correlated with fatigue (r=-.42, p<.001) and depression (r=-.56, p<.001), and positively correlated with marital intimacy (r=.30, p<.001). Multiple regression analysis showed that depression (β=-0.44, p<.001), fatigue (β=-0.27, p<.001), and husband's attitude (β=-0.19, p=.007) had significant effects on the QoL of infertile women, accounting for 40.5% of the variance in infertility-related QoL. Conclusion: The study provides insights into how infertile women's infertility-related QoL was influenced by depression, fatigue, and their husbands' attitudes regarding infertility treatment. To improve infertile women's infertility-related QoL, healthcare providers should consider developing strategies to decrease depression and fatigue in infertile women and to address their husbands' attitudes.

Effects of Rain Water Sampler on the Results of Analysis (雨水採取機가 雨水成分에 미치는 影響)

  • 李敏熙;韓義正;辛燦基;韓振錫
    • Journal of Korean Society for Atmospheric Environment
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    • v.3 no.2
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    • pp.53-61
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    • 1987
  • Automatic and manual rain smaplers wre installed at the roof of National Institute of Environmental Research (NIER), and the rain sampling and measurement were conducted during the period April to August 31, 1987. The rain sampling and measurement were carried out in the following manners: The 1st : Acidity and conductivity were measured entirely by automatic rain sampler (continuous measurement) The 2nd : Acidity and conductivity wrer measured in the laboratory with the sample that was taken out of automatic rain sampler. The 3rd : Acidity and conductivity were measured in the laboratory with the sample that was taken out of manual rain sampler. Afterwards, those different measurement values were compared each other and the following conclusions were obtained: 1) The pH of the continous measurement by the automatic sampler was lower than that of the laboratory measurement, and it was reversed in case of the conductivity. 2) The significance was recognized at 5% risk ratio for the population mean of difference of the measurement values of the pH and conductivity from both samples. 3) The significance was not recognized at 5% risk ratio by the analysis of variance by one way layout for the pH and conductivity. 4) The significance was recognized at 5% risk ratio by the analysis of variance by two way layouts for the pH conductivity. 5) The significance was recognized at 5% rrisk ratio for the differences of the pH values obtained by oboth samplers, and no significance was recognized for conductivity. 6) In comparison of the measurement values from the two samplers were shown a good correlation for pH; correlation coefficient (r) = 0.63, and regression equation Y = 0.53X + 2.78. For conductivity, the correlation was also excellent; correlation coefficient (r) = 0.53 and regression equation Y = 0.63X + 5.65.

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Sensory Difference Testing: The Problem of Overdispersion and the Use of Beta Binomial Statistical Analysis

  • Lee, Hye-Seong;O'Mahony, Michael
    • Food Science and Biotechnology
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    • v.15 no.4
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    • pp.494-498
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    • 2006
  • An increase in variance (overdispersion) can occur when a binomial statistical analysis is applied to sensory difference test data in which replicate sensory evaluations (tastings) and multiple evaluators (judges) are combined to increase the sample size. Such a practice can cause extensive Type I errors, leading to serious misinterpretations of the data, especially when traditional simple binomial analysis is applied. Alternatively, the use of beta binomial analysis will circumvent the problem of overdispersion. This brief review discusses the uses and computation methodology of beta binomial analysis and in practice evidence for the occurrence of overdispersion.

Elastic Resistance Exercise for the Elderly on the Magnitude of Frequency and Variability of Ground Reaction Force Signals during Walking (고령자 보행 시 탄성저항운동이 지면반력 신호의 주파수 크기와 variability에 미치는 영향)

  • Seo, Se-Mi;Ryu, Ji-Seon
    • Korean Journal of Applied Biomechanics
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    • v.18 no.4
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    • pp.49-57
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    • 2008
  • The purpose of this study was to determine the effects of 12-week elastic resistance exercise for the elderly on the magnitude of frequency and variability of ground reaction force signals. To this aim, total 12 elderly women aged in their 70 were participated in this study and asked to do a 12-week elastic resistance exercise program. FFT(fast Fourier Transform) was used to analyze the frequency domain analysis of the ground reaction forces's signals and an accumulative PSD (power spectrum density) normalized by support phase of walking was calculated to reconstruct the certain signals. To estimate the gait stability between the before and after exercise, values of variability were determined in a coefficient of variance. The magnitude of frequency and variability analysis for media-lateral signal revealed significantly less after exercise (p<.05). In contrast, variability of this signal's frequency that have used to evaluate the local stability during walking exhibited significantly greater after exercise(p<.05). In summary, magnitude frequency and variability of media-lateral ground reaction force's signal were significantly changed after a 12-week elastic resistance exercise.

Development of Mathematical Model to Predict Specific Wear Rates of Graphite Seal (흑연 씰의 비마모율 예측에 관한 수학적 모델 개발)

  • Kim, Yeonwook;Kim, Jaehoon;Park, Sunghan;Lee, Hwangyu;Kim, Beomkeun;Lee, Seongbeom;Kwak, Jae Su
    • Journal of the Korean Society of Propulsion Engineers
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    • v.18 no.4
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    • pp.67-73
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    • 2014
  • The dry sliding wear behavior of graphite that is used as the sealing material to cut off hot gas was evaluated as a function of applied load, sliding speed and temperature. The reciprocating wear tests were carried out at room temperature and elevated temperatures. An attempt has been made to develop a mathematical model by response surface methodology and an analysis of variance technique was applied to confirm the validity of the developed model. Also, the wear mechanism was compared through the observation of the worn surface by SEM analysis.

A phytogeographical study of Sasa borealis populations based on AFLP analysis (AFLP 마커를 이용한 조릿대 개체군의 식물지리학적 연구)

  • Kim, Il Ryong;Yu, Dasom;Choi, Hong-Keun
    • Korean Journal of Plant Taxonomy
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    • v.45 no.1
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    • pp.29-35
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    • 2015
  • Sasa borealis (Hack.) Makino & Shibata is widely distributed in South Korea. With amplified fragment length polymorphism (AFLP) markers, we analyzed the genetic diversity of S. borealis to predict and measure the phytogeographical factors of these populations. Relatively high levels of genetic diversity (PPL = 37.2%, h = 0.143, I = 0.205) and genetic differentiation ($G_{ST}$ = 0.324, ${\theta}^B$ = 0.395) were confirmed in populations of S. borealis. Moreover, an analysis of molecular variance (AMOVA) showed that the rate of differentiation among the populations was 47.7%. The results showed that genetic diversity is inversely proportional to the latitude of the S. borealis populations, indicating that the distribution of S. borealis may have extended from lower to higher latitudes. This method of investigating the correlation between genetic diversity and latitude presents critical information for estimating changes in distributions and plant conservation due to climate change.

A Study on the Relationships between the Stock Markets of Korea, the US, China, and Japan: Focusing on the Pre- and Post-COVID-19 Periods (한국, 미국, 중국, 일본 주식시장 간 동적 관계에 관한 연구: 코로나19 전후 비교 중심으로)

  • Yong-Hao Yu;Se-ryoong Ahn
    • Asia-Pacific Journal of Business
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    • v.15 no.2
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    • pp.143-157
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    • 2024
  • Purpose - This paper aims to analyze the relationship and correlation between the stock markets of Korea, the US, China, and Japan before and after the outbreak of COVID-19. Design/methodology/approach - This study conducted an empirical analysis using the stock market data from January 2016 to June 2023 for the representative market indices of Korea, the US, China, and Japan. The analysis employed the VAR model, Granger causality test, impulse response function, and variance decomposition. Findings - Analyzing the relationships of these stock markets before and after the outbreak of COVID-19, we obtained the following results. (i) The influence of the U.S. stock market was found to be absolute regardless of the COVID-19 period, and the rise in the U.S. stock market led to rises in other stock markets. (ii) The Chinese stock market had a significant negative impact on the U.S., Korean, and Japanese stock markets before COVID-19, but this influence disappeared after COVID-19. This suggests that the Chinese market exhibited unique characteristics different from the global market after COVID-19. (iii) Analyzing the period excluding the first quarter of 2020, when global stock market volatility was extremely high due to the spread of COVID-19, we found that the results were very similar to the analysis including the first quarter of 2020. Therefore, it is difficult to argue that the increased uncertainty during this period distorted the relationships among the stock markets of these four countries. Research implications or Originality - We anticipate that these findings will offer valuable insights for both individual and institutional investors, aiding them in portfolio diversification and risk mitigation.