• Title/Summary/Keyword: Correlations Analysis

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Development of Performance Analysis Program for an Axial Compressor with Meanline Analysis (평균반경해석법을 이용한 축류압축기 성능해석 프로그램 개발)

  • Park, Jun-Young;Park, Moo-Ryong;Choi, Bum-Suk;Song, Je-Wook
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.33 no.2
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    • pp.141-148
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    • 2009
  • Axial-flow compressor is one of the most important parts of gas turbine units with axial turbine and combustor. Therefore, precise prediction of performance is very important for development of new compressor or modification of existing one. Meanline analysis is a simple, fast and powerful method for performance prediction of axial-flow compressors with different geometries. So, Meanline analysis is frequently used in preliminary design stage and performance analysis for given geometry data. Much correlations for meanline analysis have been developed theoretically and experimentally for estimating various types of losses and flow deviation angle for long time. In present study, meanline analysis program was developed to estimate compressor losses, incidence angles, deviation angles, stall and surge conditions with many correlations. Performance prediction of one stage axial compressors is conducted with this meanline analysis program. The comparison between experimental and numerical results show a good agreement. This meanline analysis program can be used for various types of single stage axial-flow compressors with different geometries, as well as multistage axial-flow compressors.

Mediating Effects of Irrational Beliefs on the Relationships Between Autonomy of Psychological Growth Environment and Behavioral Anger Responses Perceived by Middle School Students (중학생이 지각한 심리적 성장환경의 자율성과 분노행동의 관계에서 비합리적 신념의 매개효과)

  • Kim, Taeeun
    • Journal of Families and Better Life
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    • v.34 no.6
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    • pp.27-40
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    • 2016
  • This study examined the mediating effects of irrational beliefs on the relationships of middle school students' autonomy of psychological growth environment and behavioral anger responses(impulsive reaction, verbal aggression, physical confrontation and indirect expression). A sample of 346 first and second year students of middle school participated in the autonomy of psychological growth environment scale, the irrational beliefs scale and behavioral anger responses scale. Pearson's correlation analysis and regression analysis were performed. The results showed that: ⑴ The relations among autonomy of psychological growth environment, irrational beliefs and behavioral anger responses were significant. The autonomy of psychological growth environment had negative correlations with irrational beliefs and behavioral anger responses. Irrational beliefs produced positive correlations with behavioral anger responses. There were positive correlations among the subtypes of behavioral anger responses. ⑵ There were mediating effects of irrational beliefs between autonomy of psychological growth environment and behavioral anger responses. The effects of autonomy of psychological growth environment on impulsive reaction, physical confrontation and indirect expression were fully mediated by irrational beliefs. However, the effect of autonomy of psychological growth environment on verbal aggression was partially mediated by irrational beliefs. This study demonstrated that irrational beliefs mediate the relationship between autonomy of psychological growth environment and behavioral anger responses.

The Ecological Variables on Adolescents' Runway Impulse (청소년의 가출충동에 영향을 미치는 생태학적 변인)

  • Nam, Mi-Kyung;Lee, Kyung-Nim
    • Journal of Families and Better Life
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    • v.27 no.4
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    • pp.41-54
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    • 2009
  • This study focused on the ecological variables that affect adolescents' runway impulse. For the organisms, self-esteem, impulse control, school achievement and runway experience, for the microsystems, family, school and peer environment, for the mesosystems, family-peer relationships and family-school relationships, and for the exosystem, neighborhood environment were included. The sample consisted of 651 eleventh grade adolescents. Instruments were the Runway Impulse Scale(Nam, 2001) and Index of organisms, microsystems, mesosystems, and exosystem variables. Statistics and methods used for the analysis were Cronbach's alpha, frequency, percentage, t-test, Pearson's correlation and multiple Regression. Several major results were found from the analysis. First, no sex difference was found in adolescents' runway impulse. Second, runway impulse of male and female adolescents showed positive correlations with runway experience, parental marital conflict, dissatisfactions of school life and exposure to friends with problems behavior but negative correlations with self-esteem, impulse control, school achievement, parental support and supervision, teacher support, family-peer relationships and neighborhood environment. Female adolescents' runway impulse stowed negative correlations with family-school relationships. Third, the most important variable predicting male adolescents' runway impulse was exposure to friends with problems behavior, the most important variable for female was self-esteem.

Correlations between Obtaining Fever Management Information from the Internet and Knowledge and Practices of Fever Management by Mothers of Infants and Toddlers (영유아 어머니의 발열관리 인터넷 정보 획득과 발열관리 지식 및 수행 간의 관계)

  • Kim, Hyeon Jin;Koo, Hyun Young
    • Child Health Nursing Research
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    • v.26 no.2
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    • pp.190-200
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    • 2020
  • Purpose: This study was conducted to identify correlations between how much fever management information mothers obtained from the internet and their actual knowledge and practices of fever management. Methods: This was a descriptive survey of 172 mothers with children aged between 0 and 3 attending five daycare centers located in the city of Daegu. Descriptive statistics, the independent t-test or one-way analysis of variance, and Pearson correlation coefficients were used for data analysis. Results: In total, 75% of the mothers had searched the internet for information on fever management. The overwhelming majority (92.2%) used information from the internet to help manage fever in their children. Positive correlations were found between acquiring fever management information from the internet and fever management practices (r=.18, p=.038), and between mother's knowledge and practices of fever management (r=.27, p<.001). Conclusion: Based on the results of this study, to improve fever management practices, it is necessary to increase mothers' knowledge. Therefore, resources should be developed to augment mothers' knowledge of fever management through the internet.

A Study on the Burning Velocity Correlation of LFG Mixed Fuel Using Numerical Analysis (수치계산을 이용한 LFG 혼합연료의 연소속도 상관식에 관한 연구)

  • Lee, Chang-Eon;O, Chang-Bo;Jeong, Ik-San
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.24 no.11
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    • pp.1513-1522
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    • 2000
  • In this study, the burning velocities of LFG and LFG mixed fuels have been numerically determined. C3 reaction mechanism involving 92 species and 621 reactions was adopted in the calculation. The computed burning velocities using C3 mechanism show good agreements with experimental data. Based on numerical results, the maximum burning velocities of LFG and LFG mixed fuels were correlated as a function of CH$_4$ and LFG component percentage at stoichiometric conditions. In addition, the correlations of burning velocities of LFG and LFG mixed fuels were obtained over a wide range of the equivalence ratio. The numerical results are well agreed with the burning velocity correlations. The burning velocity correlations for LFG and LFG mixed fuels suggested in this study can be applied to the practical utilization of LFG.

Analysis of Correlations among Bone Mineral Density, Serum Lipid Levels, and Cognitive Function in the Elderly with Dementia (치매노인에서 골밀도 및 혈중 지질농도와 인지기능과의 상관관계 분석)

  • Kim, Soo-Han;Kim, Ji-Sung
    • Journal of the Korean Society of Physical Medicine
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    • v.7 no.2
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    • pp.149-155
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    • 2012
  • Purpose : The purpose of this study was to analyze the correlations among bone mineral density(BMD), serum lipid levels, and cognitive function in the elderly with dementia. Methods : We recruited seventy elderly with dementia(men=35, women=35) to participate in the Korean mini mental state examination(K-MMSE). Their T-scores and serum lipid levels were analyzed for correlation analysis. Results : The results of this study showed that there are significant correlations between cognitive function and three factors BMD, low-density lipoprotein cholesterol(LDL-C) level, and total cholesterol(TC) level. The cognitive function scores increased proportionally with BMD but were inversely proportional to LDL-C and TC levels. There were no significant relations among cognitive function, high-density lipoprotein cholesterol(HDL-C) level, and triglyceride(TG) level. Conclusion : These results indicate that there is a direct proportionality between cognitive function and BMD and inverse proportionalities between cognitive function and LDL-C level and between cognitive function and TC level. Therefore, these levels can be indices for preventing and predicting dementia.

Poor Correlation Between the New Statistical and the Old Empirical Algorithms for DNA Microarray Analysis

  • Kim, Ju Han;Kuo, Winston P.;Kong, Sek-Won;Ohno-Machado, Lucila;Kohane, Isaac S.
    • Genomics & Informatics
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    • v.1 no.2
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    • pp.87-93
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    • 2003
  • DNA microarray is currently the most prominent tool for investigating large-scale gene expression data. Different algorithms for measuring gene expression levels from scanned images of microarray experiments may significantly impact the following steps of functional genomic analyses. $Affymetrix^{(R)}$ recently introduced high-density microarrays and new statistical algorithms in Microarray Suit (MAS) version 5.0$^{(R)}$. Very high correlations (0.92 - 0.97) between the new algorithms and the old algorithms (MAS 4.0) across several species and conditions were reported. We found that the column-wise array correlations had a tendency to be much higher than the row-wise gene correlations, which may be much more meaningful in the following higher-order data analyses including clustering and pattern analyses. In this paper, not only the detailed comparison of the two sets of algorithms is illustrated, but the impact of the introducing new algorithms on the further clustering analysis of microarray data and of possible pitfalls in mixing the old and the new algorithms were also described.

Factor analysis on infiltration using correlations (상관성 분석을 통한 침입수 발생 영향인자 분석)

  • Ryu, Jae-Na;Oh, Je-Ill;Choi, Ick-Hoon
    • Journal of Korean Society of Water and Wastewater
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    • v.25 no.2
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    • pp.185-192
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    • 2011
  • Pearson's correlation was used to determine relations between infiltration and affecting factors using flow monitoring data measured in 24 areas with different characteristics. Factors showed relatively high correlations than others were indexed to determine infiltration rates of the study area. Among 8 factors(service area, sewer length, sewer diameter, multiplier of sewer length and diameter, number of manholes, population, number of properties, number of households) tested, the multiplier of sewer length and diameter, the number of population and the number of household in each service area indicated higher correlation coefficient(>0.8) than others. The goodness of fitness of linear regressions between infiltration and the factors followed the order: sewer length and diameter(0.68)> population(0.65)> number of household(0.60). Infiltration rates calculated by the multiplier of sewer length and diameter, the number of population and the number of household in each service area were 0.046~1.0396 $m^{3}/d{\cdot}mm-km$, 0.0917~1.7355 $m^{3}/capita{\cdot}d$, 0.196~4.529 $m^{3}/household {\cdot}d$ respectively. After sewerage rehabilitation work of the area, the infiltration rates calculated by above factors with high correlations are expected to be used for comparing effectiveness of the work once they are estimated under the same flow measuring conditions.

Stochastic finite element analysis of composite plates considering spatial randomness of material properties and their correlations

  • Noh, Hyuk-Chun
    • Steel and Composite Structures
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    • v.11 no.2
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    • pp.115-130
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    • 2011
  • Considering the randomness of material parameters in the laminated composite plate, a scheme of stochastic finite element method to analyze the displacement response variability is suggested. In the formulation we adopted the concept of the weighted integral where the random variable is defined as integration of stochastic field function multiplied by a deterministic function over a finite element. In general the elastic modulus of composite materials has distinct value along an individual axis. Accordingly, we need to assume 5 material parameters as random. The correlations between these random parameters are modeled by means of correlation functions, and the degree of correlation is defined in terms of correlation coefficients. For the verification of the proposed scheme, we employ an independent analysis of Monte Carlo simulation with which statistical results can be obtained. Comparison is made between the proposed scheme and Monte Carlo simulation.

A Study on the Middle and High School Student's Recognition of Beauty Arts (중고생의 미용인식에 대한 연구 -헤어 미용을 중심으로-)

  • Yoon, Eun-Young;Kim, Sung-Nam
    • Journal of the Korean Society of Fashion and Beauty
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    • v.6 no.1
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    • pp.48-52
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    • 2008
  • The purpose of the study is to look at the middle and high school student's recognition of beauty Arts. The collected data were analyzed by frequency analysis, factor analysis, reliability test, t-test, correlations analysis, from which the result is as follows. Firstly, the lower levels of beauty art are comprehensive interest, personal interest professional interest, effort type, management type and consumption type. Secondly, Beauty art interest and attitude by gender and school levels showed meaningful difference. Thirdly, there is meaningful correlations between beauty art interest and beauty art attitude.

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