• Title/Summary/Keyword: Mean-Variance Analysis

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A Study of the Basic Slacks Pattern for the Fatty Body -The subject of middle-aged women- (비만체형을 위한 기본 Slacks 원형연구 -중년기 부인을 중심으로-)

  • 이영희
    • Journal of the Korean Home Economics Association
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    • v.25 no.3
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    • pp.27-36
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    • 1987
  • The purpose of this study was to develop a slacks pattern drafting method for the fatty women of 40∼55 aged Korean women who are more than 1.5 Rohrer's index on the basis of their physical characteristics. The study was composed as follows; 1. Body measurement and statistical analysis: One hundred and thirty women between the ages of 40∼55 over 1.5 Rohrer's index were measured on 21 items. Mean, standard deviation, variance, maximum, minimum, range were computed. 2. 4 types of conventional slacks pattern were collected. The most accepted conventional slacks pattern was decided through wearing test. The new pattern was based onthe most accepted conventional pattern, and developed through wearing tests. 3. Evaluation of the new pattern drafting method: The sensory evaluation was applied to evaluate the new pattern by comparing is with the most accepted conventional pattern. According to the statistical analysis of the result of the 12 items, all the items showed significant differences (α 0.01) between the two, with the new pattern having higher scores.

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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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Robust Optimization of a Lens System for a Mobile Phone Camera (휴대폰 카메라용 렌즈 시스템의 강건최적설계)

  • Jung, Sang-Jin;Min, Jun-Hong;Choi, Dong-Hoon;Kim, Ju-Ho
    • Korean Journal of Computational Design and Engineering
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    • v.15 no.5
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    • pp.325-332
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    • 2010
  • A lens system for mobile phone cameras is comprised of various lenses and designed so as to satisfy design requirements for responses such as a modular transfer function (MTF). However, it is difficult to manufacture and assemble camera modules to maintain the same performance compared with the designed camera modules, because of uncertainty. We should always design a lens system by considering uncertainty that can be caused by errors in the manufacturing and assembly process of mobile phone cameras. The robust optimization offers tools of making robust decisions with the consideration of design parameters, uncontrollable parameters, and the variance of the system. Using an efficient reliability analysis method and an optimization algorithm, we obtained robust optimization results that maximize the mean of MTF and minimize the standard deviation and proposed a new robust design process for a lens system.

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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The Influential Factors on Compassion Fatigue in Hospital Nurses (병원간호사의 공감피로 영향요인)

  • Lee, Hyeon Jeong;Min, Hye Sook
    • Journal of muscle and joint health
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    • v.21 no.3
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    • pp.236-245
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    • 2014
  • Purpose: The purpose of this study was to identify influential factors on compassion fatigue in hospital nurses. Methods: A cross-sectional descriptive design was conducted with a survey of 358 general hospital nurses in Busan Gyeongnam area. For data analysis, descriptive statistics, Pearson's correlation coefficients, and multiple regression were performed using SPSS/WIN 18.0 for Windows. Results: The mean score was 28.53 in compassion fatigue. As a result of multiple regression analysis, empathic ability, stress coping strategy, current workplace, and academic background were statistically significant predictors explained 26.0% of the variance of compassion fatigue. Conclusion: It was suggested to consider emphatic ability, stress coping strategy, workplace, and academic background when developing a program available for preventing and easing nurses' compassion fatigue.

Nutrition Service Need Assessment for Industrial Employees (사업체 근로자의 영양서비스 요구도 분석)

  • Jang, Mi-Ra;Hong, Wan-Su
    • Journal of the Korean Dietetic Association
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    • v.6 no.1
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    • pp.26-32
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    • 2000
  • The purposes of this study were to assess the importance and performance level of nutrition service in views of industrial employees and to explore the ways to improve the nutrition service quality. A survey of industrial foodservice operations located in Korea was undertaken and detailed information was collected from each, including surveys of 994 industrial employees. Statistical data was analysed by SAS PC 6.04 for descriptive analysis, t-test, and analysis of variance. The whole industrial employees assessed the importance and performance of the dieticians' role on nutrition service as '4.03' and '3.32' out of 5 respectively, which suggests that the industrial nutrition service needs to be improved. The variables which received higher scores than the average mean were safe meal provision, sanitation management and equipment & facilities management, whereas the score of individual nutrition counselling was low compared to other variables of nutrition service. The groups who scored low performance were characterized by labor work, experience with less than 10 years, single, aged below 29 years old, and female.

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Relationships between Print Concepts and Language Ability in 4-to 6-year old Korean Children (한국 아동의 인쇄물 개념 습득과 언어능력의 관계)

  • Kim, Sun Hee;Kim, Myoung Soon
    • Korean Journal of Child Studies
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    • v.25 no.6
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    • pp.371-383
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    • 2004
  • In this study, 197 4- to 6- year-old Korean children wereindividually tested with Concepts about Print(CAP Clay, 2000), the Picture Vocabulary Test(Kim, Jang, Lim & Bak, 1996), Korean-Wechsler Preschool and Primary Scale of Intelligence : Verbal Test (K-WPPSI), and the Basic Academy Skills Assessment : Reading(Kim, 2000). Data were analyzed by Pearson-correlation, analysis of variance, and factor analysis. There were significant differences of CAP mean scores by age. Within the subcategories of CAP, Book Orientation Concepts and Print-convention were acquired earlier than other subcategories, followed by Print-direction, Print-order and Advanced Print Concepts in that order. The scores of CAP were positively correlated with the Picture Vocabulary Test, the K-WPPSI verbal test and the reading test.

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Pedestrian Protection System Design for SUV Using the Design of Experiments (실험계획법을 이용한 SUV의 보행자 보호 시스템 설계)

  • Lee, Youngmyung;Choe, Wonseok;Park, Gyung-Jin
    • Transactions of the Korean Society of Automotive Engineers
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    • v.24 no.1
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    • pp.24-32
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    • 2016
  • The mortality rate of car-pedestrian accidents is quite high, compared to the frequency of accidents. Researches on pedestrian protection are being actively performed worldwide. The A-pillar and lower part of the wind shield cause the most serious damage to the pedestrians. Typical devises to protect the pedestrians are the hood lift system and pedestrian airbag. The design of such devices for an sport utility vehicle is performed based on a design process using design of experiments (DOE). The design results are obtained by an orthogonal array (OA), analysis of mean (ANOM) and analysis of variance (ANOVA). A metamodel is also used in the design process.

Variable Selection Theorem for the Analysis of Covariance Model (공분산분석 모형에서의 변수선택 정리)

  • Yoon, Sang-Hoo;Park, Jeong-Soo
    • Communications for Statistical Applications and Methods
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    • v.15 no.3
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    • pp.333-342
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    • 2008
  • Variable selection theorem in the linear regression model is extended to the analysis of covariance model. When some of regression variables are omitted from the model, it reduces the variance of the estimators but introduces bias. Thus an appropriate balance between a biased model and one with large variances is recommended.

Optimal Ply Design of Laminated Composite Plate with a Hole Considering Vibration (진동을 고려한 원공복합적층판의 최적적층설계)

  • 홍도관;김동영;최경호;안찬우
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.13 no.6
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    • pp.423-429
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    • 2003
  • On this study. we improved the efficiency applying algorithm that is repeatedly using table of orthogonal array in discrete design space and filling a defect of gradient method in continuous design space. we showed optimal ply angle that maximized 1st natural frequency 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 of optimization achievement repeatedly using statistical table of orthogonal array of experimental design and the BFGS optimal design method.