• 제목/요약/키워드: Statistical power of test

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Comparative analysis on reproducibility among 5 intraoral scanners: sectional analysis according to restoration type and preparation outline form

  • Park, Ji-Man
    • The Journal of Advanced Prosthodontics
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    • v.8 no.5
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    • pp.354-362
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    • 2016
  • PURPOSE. The trueness and precision of acquired images of intraoral digital scanners could be influenced by restoration type, preparation outline form, scanning technology and the application of power. The aim of this study is to perform the comparative evaluation of the 3-dimensional reproducibility of intraoral scanners (IOSs). MATERIALS AND METHODS. The phantom containing five prepared teeth was scanned by the reference scanner (Dental Wings) and 5 test IOSs (E4D dentist, Fastscan, iTero, Trios and Zfx Intrascan). The acquired images of the scanner groups were compared with the image from the reference scanner (trueness) and within each scanner groups (precision). Statistical analysis was performed using independent two-samples t-test and analysis of variance (${\alpha}=.05$). RESULTS. The average deviations of trueness and precision of Fastscan, iTero and Trios were significantly lower than the other scanners. According to the restoration type, significantly higher trueness was observed in crown and inlay than in bridge. However, no significant difference was observed among four sites of preparation outline form. If compared by the characteristics of IOS, high trueness was observed in the group adopting the active triangulation and using powder. However, there was no significant difference between the still image acquisition and video acquisition groups. CONCLUSION. Except for two intraoral scanners, Fastscan, iTero and Trios displayed comparable levels of trueness and precision values in tested phantom model. Difference in trueness was observed depending on the restoration type, the preparation outline form and characteristics of IOS, which should be taken into consideration when the intraoral scanning data are utilized.

The effect of dental technician's organizational commitment on the turnover intention (치과기공사의 조직몰입이 이직의도에 미치는 영향)

  • Kwon, Eun-Ja;Han, Min-Soo;Choi, Esther
    • Journal of Technologic Dentistry
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    • v.39 no.4
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    • pp.285-294
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    • 2017
  • Purpose: This study was carried out in order to examine organizational commitment in dental technicians and turnover intention level according to it, and to analyze its effects. Methods: A self-reported questionnaire survey was carried out by having convenience sampling as 200 dental technicians. An analysis of the collected data was computationally processed by using SPSS Win 19.0 program. An analytical technique was made by using statistical techniques such as frequency & percentage, t-test, One-way ANOVA analysis. The following are the analytical results of the collected materials. Results: In consequence of analyzing organizational commitment level in research subjects, there was a significant difference in the items for age, task field, job position in charge, career in dental laboratory technology, and monthly income(p<.05). The average of the item for organizational commitment level stood at 3.29, thereby having been indicated to be high. As a result of analyzing turnover intention level in research subjects, there was a significant difference in the items for task field, job position in charge, career in dental laboratory technology, and monthly income(p<.05). The average of the item for turnover intention reached 3.04, thereby having appeared to be relatively high. As for a correlation between organizational commitment and turnover intention, all variables were shown to have inverse correlation at a significant level. In consequence of conducting regression analysis in order to analyze the influence of organizational commitment upon turnover intention, a factor of having the most impact on turnover intention appeared to be normative commitment. The test value of the model was statistically significant. The explanation power about this was indicated to be 26.9%. Conclusion : In the above findings, the dental technicians are considered to need to be immersed in work with a sense of mission in performing job in charge, to strive to possibly have an opportunity of achievement and self-growth, and to perform a research and development in a manpower management strategy such as turnover prevention.

Effects of Successful aging and SOC coping strategies on the Quality of life of Middle-aged women (중년여성의 성공적 노화와 SOC 대처전략이 삶의 질에 미치는 영향)

  • Lee, Do-Young;Noh, Gie-Ok
    • The Journal of the Convergence on Culture Technology
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    • v.7 no.4
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    • pp.27-34
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    • 2021
  • This study is a descriptive research study to understand the effects of successful aging and SOC coping strategy on quality of life in middle-aged women. The study subjects were middle-aged women (40~65years old) across the country, and data were collected using a structured questionnaire. The collected data were analyzed by descriptive statistics, Independent t-test, one-way ANOVA, Pearson's correlation, and stepwise multiple regression using SPSS WIN/PC 24.0 statistics program. The study found that successful aging of middle-aged women, SOC alternative strategies and quality of life were statically correlated, and statistical significance was identified in order of successful aging(β=.41, p<.001) and SCO coping strategies(β=.17, p=.047) as variables describing quality of life. In this study, the explanatory power by the two variables was 24.7%. Therefore, in order to improve the quality of life of middle aged women, it is necessary to study and program programs to enhance the SOC coping strategy of successful aging.

An exploratory study for an evidence of electroencephalographic changes in isolated subjects for distant mental intention

  • Kim, Dae-Keun
    • Science of Emotion and Sensibility
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    • v.17 no.4
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    • pp.51-60
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    • 2014
  • This double-blind study, as a human experiment of nonlocality, investigated the effects of senders' intention on the central nervous system of a distant human receiver and it explored the roles that motivation might have in modulating these effects. Whole brain activity was measured in the receiver whom was asked to relax in a distant room for 16 minutes; the sending person directed intention of oneness toward the receiver during repeated variable-second epochs separated by variable-second non-intention epochs. The total length of intention epochs and that of nonintention epochs were balanced. Eighteen sessions were conducted. In 9 of those sessions, the sender was the receiver's lover. In another 9 of those sessions, the sender was just acquainted with the receiver before the session. The receiver's whole brain activity recorded during the intention epochs were compared with the same measures recorded during the nonintention epochs used as controls. The statistical difference between the intentions versus controls across 18 sessions was examined by paired-t test. In addition, subgroup analysis for the 9 couple sessions and 9 non-couple sessions were additionally examined by the same test. The effect of distant intentionality decreased slow waves or increased EEG fast waves mainly in frontal regions, and increased EEG coherence during the intention epochs. The effects was not statistically significant after Bonferroni correction, but the couple sessions combined showed the largest effect followed by all sessions combined. Non-couple sessions combined showed the smallest effect. The changes in EEG power mean that receiver participants became more alert during the intention epochs and the change in EEG coherence might be evidence of coherent heart influence on EEG activity. Planned comparison with specific hypothesis testing for the suggested changes in this study have to be followed for an evidence of electroencephalographic changes in isolated subjects for the distant mental intention.

The Effect of Nursing Students' Everyday Creativity and Self-Esteem on Sociality (간호대학생의 일상적 창의성, 자아존중감이 사회성에 미치는 영향)

  • Jeong, Gyeong-Sun;Park, Eui-Jeung
    • Journal of The Korean Society of Integrative Medicine
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    • v.9 no.4
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    • pp.119-127
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    • 2021
  • Purpose : The aim of this study was to examine the relationships of everyday creativity and self-esteem, with sociality in college students majoring in nursing science and to identify factors that influence sociality. Methods : In the study 209 college students majoring in nursing science in B city were surveyed for the period of July through September 2020. The collected data were analyzed using SPSS statistics 22.0 for Windows to determine the frequency, percentage ratio, average, and standard deviation. Statistical analyses included the t-test, analysis of variance, Scheffe test, Pearson correlation coefficient, and multiple regression analysis. Results : The everyday creativity of the nursing students was 3.65±0.43, self-esteem was 3.70±0.63, and sociality was 3.21±.33. Significant differences were observed for self-esteem according to the participant's grade (F=3.11, p=.027), monthly income (F=2.41, p=.050), health condition (F=4.87, p=.001) and clinical experience (t=-2.17, p=.031). Significant differences were not observed with regard to sociality. A static correlation was observed between everyday creativity and self-esteem (r=.478, p<.001) and between everyday creativity and sociality (r=.342, p<.001). Self-esteem and sociality were also statistically correlated (r=.168, p<.05). Factors that influenced the participants' sociality included monthly income (𝛽=.168, p=.015), health condition (𝛽=.178, p=.022), clinical experience (𝛽=-.161, p=.048), ability to find alternative solutions (𝛽=.245, p=.015), and in dependent nature (𝛽=.224, p=.003); The explanatory power was 15.60 %. Conclusion : More research is needed to understand the relationship between everyday creativity, self-esteem, and sociality in college students majoring in nursing science, Greater efforts are needed to develop programs that nurture the sociality of college student majoring in nursing science.

Safety Knowledge, Safety Control and Safety Performance in Early Childhood Teachers (유아교사의 안전지식, 안전통제가 안전수행에 미치는 영향)

  • Kim, Soo Hyang;An, Aun Hei
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.16 no.1
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    • pp.246-254
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    • 2015
  • This study was conducted as a descriptive study with the aim of identifying the effects of safety knowledge and safety control on early childhood teachers' safety performance. Data collection for the study was carried out between October $10^{th}$ and $30^{th}$, 2014 by surveying 187 early childhood teachers working in child day care center and kindergarten located in P, K, & Y city. Measures were subjects' safety knowledge, safety control, and safety performance. For the analysis of the data, the statistical methods of frequency, mean and standard deviation, t-test, ANOVA, Pearson's correlation coefficients, and multiple regression analysis were employed. When the category of safety performance was analyzed by general features, marital status, educational career, and degree of assistance of safety education, there were significant differences. Safety performance correlated positively with safety knowledge and safety control. Factors affecting early childhood teachers' safety performance were identified in the order of safety knowledge and safety control and the explanatory power was 60.0%. The findings of the study indicate that in order to increase early childhood teachers' safety performance, their safety knowledge and safety control have to be enhanced.

Shoes Purchasing Behavior and Wearing Satisfaction Related with Lifestyle of High School Girls (여고생의 라이프스타일에 따른 신발 구매 행동과 착용만족도)

  • Lee, So-Hyoung;Lee, Ji-Yeon;Park, Myung-Ja
    • Journal of the Korea Fashion and Costume Design Association
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    • v.12 no.2
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    • pp.75-90
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    • 2010
  • Teenagers are considered as one of important consumer groups by marketers because of their high purchasing power and impulsive purchasing propensity. Especially high school girls are most significant purchasing group of them. The purpose of this study is to investigate the effect of high school girls' lifestyle on shoes purchasing behavior and shoes wearing satisfaction. This study surveyed 428 high school girls in Seoul and Chonbuk area. Data were statistically analyzed using SAS 9.1.3 for Window. Major statistical methods are factor analysis, Cronbach's ${\alpha}$ coefficient, cluster analysis, frequency analysis, Chi-square test, multiple regression analysis, ANOVA and Duncan test. The shoes purchasing behavior is significantly different according to students' lifestyle. Activity-pursuing group's major shoes purchasing factor is practical use and fashion & scholar-pursuing group's major shoes purchasing factors are fashion and brand. Relationship between lifestyle and shoes purchasing pattern is as follows. Activity-pursuing group and fashion & scholar-pursuing group purchased shoes more frequently than family-pursuing group. Fashion & scholar-pursuing-group purchased shoes for the harmony of suit and shoes. As for wearing satisfaction, design is the primary factor and price was the least significant factor in sports shoes, while durability is the primary factor and material is the least significant factor for the casual shoes.

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Analysis of the Effect of Yellow Carpet Installation according to Driving Behavior with Eye Tracking Data (가상주행실험 기반 운전자 시각행태에 따른 옐로카펫 설치 효과 분석)

  • Sungkab Joo;Dohoon Kim;Hyemin Mun;Homin Choi
    • The Journal of The Korea Institute of Intelligent Transport Systems
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    • v.22 no.5
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    • pp.43-52
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    • 2023
  • Traffic accidents among children have been decreasing after the installation of yellow carpets. However, the explanatory power of the causal relationship between yellow carpet installation and traffic accidents is still insufficient. The yellow carpet effect was analyzed in greater depth using virtual reality (VR) simulation experiments in various situation that could not be evaluated in existing actual vehicle research studies due to difficulties or risks in implementation. A target site where an actual yellow carpet was installed was selected and, implemented into a virtual environment. Subjects were made to, were gaze measurement equipment and ride the simulator. The visual/driving behavior before and after yellow carpet installation was compared, and a t-test analysis was performed for statistical verification. All the results were found to be statistically significant.

A Study on the Stress Analysis of Launch Vehicle due to Acoustic Loads (음향 하중에 의한 발사체의 응력해석에 관한 연구)

  • Yeon,Jeong-Heum;Yun,Seong-Gi;Jang,Yeong-Sun;Lee,Yeong-Mu
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.31 no.8
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    • pp.91-98
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    • 2003
  • In the structural analysis of a launch vehicle, the construction of loading functions and the determination of responses to them are very important. Among many kinds of loads, acoustic load generated by exhaust is a random load that can be described in a statistical manner. In this study, loading functions corresponding to the acoustic loads are constructed and applied to the structural analysis of launch vehicle. Acoustic loading functions are constructed using source allocation method. Structural analyses are carried out by using finite element modelling and frequency response function of finite element model. The stresses resulting from acoustic loads and acceleration power spectral density functions at interfaces of each section are calculated. These analyses are essential for the development of environmental test specifications and associated dynamic design requirements which are necessary to ensure overall vehicle reliability.

Analysis of Public System's Quality and User Behavior Using PLS-MGA Methodology : An Institutional Perspective (PLS-MGA 방법론을 활용한 제도론적 관점에서의 공공제도 품질과 사용자 행태의 분석)

  • Lee, Jae Yul;Hwang, Seung-June
    • Journal of Korean Society of Industrial and Systems Engineering
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    • v.40 no.2
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    • pp.78-91
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    • 2017
  • In this study, we conducted a comparative study on user's perception and behavior on public system service (PSS) using institutionalism theory and MGA (multi-group analysis) methodology. In particular, this study focuses on how institutional isomorphism is applied to public system services and how MGA can be implemented correctly in a variance based SEM (structural equation model) such as PLS (partial least square). A data set of 496 effective responses was collected from pubic system users and an empirical research was conducted using three segmented models categorized by public proximity theory (public firms = 113, government contractors = 210, private contractors = 173). For rigorous group comparisons, each model was estimated by the same indicators and approaches. PLS-SEM was used in testing research hypotheses, followed by parametric and non-parametric PLS-MGA procedures in testing categorical moderation effects. This study applied novel procedures for testing composite measurement invariance prior to multi-group comparisons. The following main results and implications are drawn : 1) Partial measurement invariance was established. Multi-group analysis can be done by decomposed models although data can not be pooled for one integrated model. 2) Multi-group analysis using various approaches showed that proximity to public sphere moderated some hypothesized paths from quality dimensions to user satisfaction, which means that categorical moderating effects were partially supported. 3) Careful attention should be given to the selection of statistical test methods and the interpretation of the results of multi-group analysis, taking into account the different outcomes of the PLS-MGA test methods and the low statistical power of the moderating effect. It is necessary to use various methods such as comparing the difference in the path coefficient significance and the significance of the path coefficient difference between the groups. 4) Substantial differences in the perceptions and behaviors of PSS users existed according to proximity to public sphere, including the significance of path coefficients, mediation and categorical moderation effects. 5) The paper also provides detailed analysis and implication from a new institutional perspective. This study using a novel and appropriate methodology for performing group comparisons would be useful for researchers interested in comparative studies employing institutionalism theory and PLS-SEM multi-group analysis technique.