• Title/Summary/Keyword: Variance of Analysis

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A Study on the Improvement Buckling Strength of Laminated Composite Plate by Taguchi Method (다구찌법을 이용한 복합적층판의 좌굴강도 개선에 관한 연구)

  • 구경민;홍도관;김동영;박일수;안찬우;한근조
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2003.06a
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    • pp.1362-1365
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    • 2003
  • On this study. we improved the efficiency applying algorithm that is repeatedly using orthogonal array in discrete design space and filling a defect of gradient method in continuous design space. we showed optimal ply angle that maximized buckling strength of CFRP laminated composite plate without a hole and with a hole by each aspect ratio. In the case of CFRP laminated composite plate without a hole, we confirmed the reliance and efficiency of algorithm in comparison with the result optimization achievement repeatedly using statistical orthogonal array of experimental design.

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A Study on Self-concept, Shopping Orientation and Store Patronage Behavior of College Women's Fashion Life-style Segments (여대생의 패션 라이프 스타일에 따른 자아개념, 쇼핑성향, 상점애고에 관한 연구)

  • 정혜영
    • Journal of the Korean Society of Costume
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    • v.25
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    • pp.201-213
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    • 1995
  • The purposes of the study were (1) to seg-ment the female college apparel market based on fashion life style and (2) to develop a pro-file of each segment regard to self-concept, shopping orientation and patronage behavior. The data were collected through questionnaire by random sample of 526 female college students. By cluster analysis of lifestyle factors, three groups were identified, (fashion leaders, fashion followers and fashion aversion) Three groups were then compared through multivariate analysis of variance and chi-square statistics on 10 self-concept variables, 6 shopping statistics on 10 self-concept variables, 6 shopping orientation factors and 1 patronage behavior variable. Significant difference were found among the three groups on all these variables which indi-cate that fashion lifestyle can be a useful base for segmenting female apparel market and these groups are unique in terms of self-con-cept, shopping orientation and patronage behavior.

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Harmonics Analysis of AC High Speed Railroad(HSR) System using Probabilistic Approach (확률론적 방법을 이용한 교류 고속철도 시스템의 고조파 해석)

  • Song Hak-Seon;Lee Jun-Kyong;Kim Jin-O;Kim Hyong-Chul
    • Proceedings of the KSR Conference
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    • 2005.05a
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    • pp.782-787
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    • 2005
  • Magnitude of generated harmonic currents along with the operation of AC traction has nonlinear characteristics, and generated harmonic currents for high speed traction are more and more in high speed railroad(HSR) systems, especially. This paper presents probabilistic approximation method for the harmonic currents analysis about the operating speed of AC traction. To use probabilistic method for HSR system, probability density function(PDF) for collected operating speed based measure data is calculated. Mean and variance of harmonic currents of single traction are obtained based on the operating speed PDF and electrical traction model. The results of Monte Carlo Simulation(MCS) are in well accordance with the experimental and analytic methods. The harmonics of different number of trainloads are systematically investigated. It is assessed by the total demand distortion(TDD) for the HSR system.

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An Empirical Study on Performance of Six Sigma Tools in Korean Service Industry (한국 서비스산업의 6시그마 기법 시행과 그 성과에 관한 실증적 연구)

  • 장대성;양종곤;황인천
    • Journal of Korean Society for Quality Management
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    • v.32 no.1
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    • pp.1-20
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    • 2004
  • Six sigma has been the most influential management innovation program since 1996 in Korea. As a result of successful implementation of 6 sigma, there have been a number of dramatic quality improvement cases. However, no empirical study of 6 sigma implementation study has done especially in the service industry of Korea. This article reviews status of finance companies which implemented 6 sigma programs in Korea and then demonstrates the relationship between 6 sigma problem solving tools such as analysis of variance and graph techniques, etc and project success and operational performance. Customer survey tools, process analysis, and documentation tool are identified as influential tools on project success. Tools of measure steps, customer survey tools, and documentation tool are found as influential tools on operational performance.

An Analysis of Patterns of Knowledge Flows of Science and Technology Using Scientific Papers and Patents (과학논문과 특허를 통한 과학기술 지식흐름의 특성분석)

  • Park, Hyun-Woo;Sung, Oong-Hyun
    • Knowledge Management Research
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    • v.9 no.1
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    • pp.39-59
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    • 2008
  • This paper is an empirical study to analyze the flow of knowledge in science and technology in order to predict technology innovation. Here, we use the information of scientific papers and patents to look into the characteristics of how knowledge is created in science, technology and industry. Based on the characteristics we find, we are able to understand the relationships between science and technology, and technology and industry. In this paper, we adopt multivariate analysis of variance (MANOVA) using scientific papers in SCI database and US patents filed by Korean inventors in order to analyze the patterns of knowledge flows of science and technology. Finally, we present the direction for future study by using the research results.

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Prediction of Tensile Strength for Friction-Welded Magnesium Alloy Part by Acoustic Emission (AE를 이용한 마그네슘 합금 마찰용접부의 인장강도 예측)

  • Shin, Chang-Min;Kang, Dae-Min;Choi, Jong-Whan;Kwak, Jae-Seob
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.11 no.2
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    • pp.34-39
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    • 2012
  • In this study, the friction welding experiment was performed by using the design of experiment. And the signal data acquired by acoustic emission sensor were analyzed to predict the tensile strength of friction welding part at friction welding process for AZ31 magnesium alloy. A dimensionless coefficient($\phi_{AE}$), which consisted in the square of AE rms and variance, was defined as the characteristic of friction welding and the prediction equation was obtained by using linear regression. As the result of analysis, it was seen that the correlation between predicted and measured values became very close and on-line prediction of the ensile strength was possible in friction welding part.

Balanced hypothesis testing for interactions of unbalanced case using analysis of means (평균분석을 이용한 교호작용의 균형 검정 방법 불균형 관측치의 경우)

  • 김병천;정강모
    • The Korean Journal of Applied Statistics
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    • v.3 no.1
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    • pp.89-103
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    • 1990
  • An analysis of mean procedure is presented for testing the significance of two factor interactions for unbalanced case. When at least one factor if at only two levels, the technique is the same as that of Ott(1967) and Nelson(1988) except that we have used the critical value by using the Sidak's multiplicative inequality. The technique can be extended to the case in which both factors more than two levels. Tables of critical values g($\alpha ; (p, q) ; v$) are given for $\alpha$=0.05 and 0.01 ; (p, q) combinations satisfying $3 \leq p \leq q \leq 5$ ; and various degrees of freedom v. We present and prove the formula of the variance of the interactions for the n-way model.

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Parameter Design of an ER Panel for Noise Reduction using Taguchi Method (다구찌법을 이용한 소음저감용 ER 패널의 파라미터 설계)

  • 윤영민;김재환;최승복
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2003.11a
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    • pp.638-642
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    • 2003
  • This paper presents a parameter design of an Electrorheological(ER) panel for noise reduction using Taguchi method. Taguchi method is a robust design method that determines control parameters in the presence of noise effect. Host structure thickness, spacer thickness, base oil viscosity and the weight ratio of ER particles are chosen for the control factors. A test setup in an SAE J1400 facility is used to analyze the sound transmission loss. The sensitivity of each factor with signal-to-noise(S/N) ratio and analysis of variance are investigated. The analysis results show that the weight ratio of ER particle and base oil viscosity of the ER fluid mostly affects the noise reduction in the presence of electric field. Based on the Taguchi method, an optimal configuration was designed and comparison is made with experimental result fer the verification.

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Rural Family Life Satisfaction: A Comparative Study of Korean and Illinois(U.S.A) Families (농촌 가정생활 만족에 대한 연구: 한국과 미국 농촌 가정을 대상으로)

  • 임정빈
    • Journal of the Korean Home Economics Association
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    • v.28 no.4
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    • pp.135-153
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    • 1990
  • This study was designed to understand family economic well-being in Korea and to compare it with that in the U.S.A. The purpose of this study was to investigate the level of rural family life satisfaction in Korea and in the U.S.A. Specific objectives were: 1. To investigate the influence of independent variabels on rural family life satisfaction, 2. To analyze the influence of socioeconomic variables and social-psychological variables on rural family life satisfaction, and 3. To find commonalities and differences between the two countries. The data, collected from 471 Korean rural households and 301 households in two counties of Ilinois, a state in the U.S.A., were analyzed by frequency distribution, pearson's correlation, one-way analysis of variance, Scheffe test, and multiple regression analysis. The results are as follows: 1. The only common tendency is that the feeling of togetherness influences family life satisfaction in the two countries. 2. The social-psychological variables correlated with each other, and these variables considerably influence rural family life satisfaction in both countries. 3. Sex, number of family members, and no talk influence family life satisfaction differently in the two countries.

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Sex Role Stereotypes among Children and the Effect of Traditional and Reversed Sex-typed Stories (유아의 성역할 고정관념 발달과 이야기 유형의 효과)

  • Hong, Yon Ae
    • Korean Journal of Child Studies
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    • v.12 no.2
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    • pp.94-110
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    • 1991
  • This study examined the developmental aspects of sex role stereotypes among children and the impact of stereotypic and reversed stereotypic sex role content on children's sex-stereotypic thinking. In study I, subjects were 181 Korean children ranging from nursery and kindergarten to grade 1. SERLI was used to measure children's sex role stereotypes. In study II, the subjects were 62 six-year-old kindergarten children of each sex. 4 experimental stories were developed haled on Hong(1991). A test-retest design was used to study sex role stereotypes and the impact of stereotypic and reversed-stereotypic sex role content. Statistical analysis of obtained data was by an ANOVA and two-way analysis of co-variance. Results revealed that 6-year-old children's sex role stereotypes were higher than 5-and 7-year-old children. Boys were higher than girls on children's sex role stereotypes. Children exposed to reversed sex role content changed significantly in the direction of reversed stereotyping.

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