• Title/Summary/Keyword: Correlations analysis

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Correlation Analysis of Design Parameters for Automotive Engine Pulley (자동차용 엔진 풀리 설계 변수의 상관관계 분석)

  • Kim H.J.;Chun D.M.;Ahn S.H.;Jang J.D.;Hong S.S.;Hwang B.C.
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2005.06a
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    • pp.139-142
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    • 2005
  • The Digital Meister is an advisory system to help the designer using the knowledge obtained from design and analysis data. In this paper, Taguchi method was applied to analyze the design parameters of automotive engine pulley. As a finite element method (FEM), ALGOR Multi-physics was used for analyzing the static analysis. As a result, two bending positions and material thickness were highly related to the maximum stress. These correlations between design parameters and analysis result will be used for supporting the design process of Digital Meister.

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Robust Optimization Design of Overhead Crane with Constraint Using the Characteristic Functions

  • Hong, Do-Kwan;Choi, Seok-Chang;Ahn, Chan-Woo
    • International Journal of Precision Engineering and Manufacturing
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    • v.7 no.2
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    • pp.12-17
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    • 2006
  • This study uses a characteristic function to explain correlations between the objective function and design variables. For the use, structural analysis and buckling analysis are carried out. the dimensional change of an original overhead crane is made based on the table of orthogonal array. For two functions or more, the effectiveness of design change can be evaluated in accordance with change in design parameters. Also, the overhead crane's weight is reduced by up to 10.55 percent while its structural stability maintained.

Elemental Correlations of Chemical Compositions in Co-rich Mn-crusts of the Republic of Marshall Islands (마샬공화국 고코발트망간각 화학조성의 원소 상관관계)

  • 황의덕;장세원;김두영
    • Journal of the Mineralogical Society of Korea
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    • v.12 no.2
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    • pp.77-90
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    • 1999
  • Characteristics and variations of chemical compositions in Co-rich crusts occurred in the EEZ of the Republic of Marshall Islands were reviewed. Correlation coefficient analysis, hierarchical cluster analysis, and Q-mode factor analysis for 62 samples were done in this study. All data were selected and gathered from the open file report of the cooperative cruise done by United States Geological Survey with Scripps Institute of Oceanography, University of Hawaii or Korea Ocean Research Development Institute. The average of crust thickness. Co content, and Ni content of 62 samples from the 21 seamounts were 30mm, 0.58 wt% and 0.40%, respectively. The mineral phases and associated elements assigned by correlation coefficients, cluster analysis and Q-mode factor analysis are following four. 1) CFA: P, Ca, CO2, Y, Sr: 2) Mn-oxide mineral: As, Mn, Co, Na: 3) Al-silicate mineral: Pd,Si, Al, Cu, Fe: 4) PGE-bearing mineral: Rh, Pt, Ir.

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Model-Ship Correlation Study on the Powering Performance for a Large Container Carrier

  • Hwangbo, S.M.;Go, S.C.
    • Journal of Ship and Ocean Technology
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    • v.5 no.4
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    • pp.44-50
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    • 2001
  • Large container carriers are suffering from lack of knowledge on reliable correlation allowances between model tests and full-scale trials, especially at fully loaded condition, Careful full-scale sea trial with a full loading of containers both in holds and on decks was carried out to clarify it. Model test results were analyzed by different methods but with the same measuring data to figure out appropriated correlations factors for each analysis methods, Even if it is no doubt that model test technique is one of the most reliable tool to predict full scale powering performance, its assumptions and simplifications which have been applied on the course of data manipulation and analysis need a feedback from sea trial data for a fine tuning, so called correlation factor. It can be stated that the best correlation allowances at fully loaded condition for both 2-dimensional and 3-dimensional analysis methods are fecund through the careful sea trial results and relevant study on the large size container carriers.

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Damage identification in suspension bridges under earthquake excitation using practical advanced analysis and hybrid machine-learning models

  • Van-Thanh Pham;Duc-Kien Thai;Seung-Eock Kim
    • Steel and Composite Structures
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    • v.52 no.6
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    • pp.695-711
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    • 2024
  • Suspension bridges are critical to urban transportation, but those in earthquake-prone areas face unique challenges. In the event of a moderate or strong earthquake, conventional linear theory-based approaches for detecting bridge damage become inadequate. This study presents an efficient method for identifying damage in suspension bridges using time history nonlinear inelastic analysis. A practical advanced analysis program is employed to model cable-supported bridges with low computational cost, generating a dataset for four hybrid models: PSO-DT, PSO-RF, PSO-XGB, and PSO-CGB. These models combine decision tree (DT), random forest (RF), extreme gradient boosting (XGB), and categorical gradient boosting (CGB) with particle swarm optimization (PSO) to capture nonlinear correlations between displacement response and damage. Principal component analysis reduces dataset dimensions, and PSO selects the optimal model. A numerical case study of a suspension bridge under simulated earthquake conditions identifies PSO-XGB as the best model for predicting stiffness reduction. The results demonstrate the method's robustness for nonlinear damage detection in suspension bridges under earthquake excitation.

Influences of Level of Alcohol Consumption and Motives for Drinking on Drinking Permissiveness in University Students (대학생의 음주 정도, 음주 동기가 음주 허용도에 미치는 영향)

  • Kim, Jong-Im;Kim, Jong-Sung;Kim, Ji-Su;Kim, Kyung-Hee
    • Journal of Korean Academy of Fundamentals of Nursing
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    • v.14 no.3
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    • pp.382-390
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    • 2007
  • Purpose: This study was done to identify the risk factors influencing drinking permissiveness in university students. Method: The participants in this descriptive survey on causal relations were 219 students enrolled in university who were selected by convenience sampling. The data collected from April to July, 2005 were used in multiple regression analysis to build a prediction model. Results: Differences in drinking permissiveness according to general characteristics were as follows: gender, drinking frequency, drinking in more than one place each time and frequency of excessive drinking. The relationship between drinking permissiveness and amount of alcohol consumption (drinking frequency/month, amount/each time) showed positive correlations. The relationship between drinking permissiveness and motives to drink (social, enhancement, confirmity, coping motives) also showed positive correlations. The causal factors of drinking permissiveness were social motives, capacity/each time and drinking frequency/month. Conclusion: The findings suggest that board intervention programs should be provided to prevent problems of excessive drinking. It is also recommended that a program be developed that can help control the variables identified in this study along with follow up study to verify the model.

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ESTIMATES OF PHENOTYPIC AND GENETIC PARAMETERS FOR WEANING AND YEARLING WEIGHTS IN BALI BEEF CATTLE

  • Djegho, Y.;Blair, H.T.;Garrick, D.J.
    • Asian-Australasian Journal of Animal Sciences
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    • v.5 no.4
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    • pp.623-628
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    • 1992
  • Records on weaning (3803) and yearling weight (2990) of beef cattle (Bibos banteng) from the Bali Cattle Improvement Project were examined. A mixed model analysis involving all main non-genetic effects (village, year of birth, season of birth, age of dam, sex of calf, all significant interactions and age at weighing as a covariate) as fixed effects and sire nested within village as a random effect was undertaken. Variance components were estimated by Henderson's Method III. Paternal half-sib components of variance and covariance were used to estimate heritabilities of weaning and yearling weights, as well as their genetic and phenotypic correlations. Heritability estimates ($\pm$ standard error) obtained by Henderson's Method III for weaning and yearling weights were $.11{\pm}.03$ and $.13{\pm}.04$, respectively while the phenotypic and genetic correlations were estimated as .32 and $.64{\pm}.10$, respectively. The parameters estimated in this study were at the lower end of the range of reported values from various breeds. It is concluded that further information should be gathered to assist in estimating genetic parameters for other economic traits of Bali beef cattle and to provide more accurate estimates for weaning and yearling weights. These parameters should then be used to formulate a selection program to enable the genetic improvement of Bali Beef cattle.

Effect of Parental-adolescent Communication on Academic Stress and Peer Relationship Perceived by High School Students (부모자녀 의사소통이 고등학생의 학업스트레스와 교우관계에 미치는 영향)

  • Kim, Yu Jeong;Lee, Eun Mi
    • The Journal of Korean Academic Society of Nursing Education
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    • v.22 no.3
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    • pp.326-333
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    • 2016
  • Purpose: The purpose of this study was to investigate the effect of parent-adolescent communication on academic stress and peer relationship perceived by high school students. Method: A total of 154 students were recruited from a high school in C city. Data were collected by means of self-reported questionnaires from September 1 to 18, 2015 and analyzed using descriptive statistics, t-test, ANOVA, Pearson correlation coefficients, and multiple regression analysis with SPSS 20.0. Results: Positive correlations were found between father-adolescent communication and peer relationship(r=.35, p<.001), and between mother-adolescent communication and peer relationship(r=.22, p=.006). Negative correlations were found between father-adolescent communication and academic stress (r=-.23, p=.004), and between mother-adolescent communication and academic stress(r=-.17, p=.039). Conclusion: These results suggest that identifying the effects of father-adolescent communication and parent-adolescent communication programs on academic stress and peer relationship is required.

The Effects of Humanistic Knowledge and Emotional Intelligence on Communication Skills of Nurses (간호사의 인문학적 소양과 감성지능 및 의사소통능력)

  • Ha, Ju Young;Jeon, So Young
    • The Journal of Korean Academic Society of Nursing Education
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    • v.22 no.3
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    • pp.264-273
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    • 2016
  • Purpose: The purpose of this study was to investigate humanistic knowledge, emotional intelligence, and communication skills among nurses and to identify factors influencing the communication skills of nurses in five hospitals. Methods: Data were collected from 248 nurses in hospitals from August 25 to September 9, 2015. Data were analyzed with descriptive statistics, t-test, ANOVA, Pearson's correlations and enter method regression analysis using the SPSS/Win 22.0 program. Results: There were significant differences in humanistic knowledge according to religion, education, work department, number of night duty, pay level satisfaction, job satisfaction, and job performance. There were significant differences in emotional intelligence according to all general characteristics. There were significant differences in communication skills according to education, position, number of night duty, and job performance. Communication skills showed positive correlations with humanistic knowledge and emotional intelligence. Emotional intelligence correlated positively with humanistic knowledge. Emotional intelligence was a significant predictor and accounted for 32% of variance in the communication skills. Conclusion: To strengthen communication skills, programs need to be complemented in order to promote humanistic knowledge and emotional intelligence for nurses.

Normalized Cross-Correlations of Solar Cycle and Physical Characteristics of Cloud

  • Chang, Heon-Young
    • Journal of Astronomy and Space Sciences
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    • v.36 no.4
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    • pp.225-234
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    • 2019
  • We explore the associations between the total sunspot area, solar north-south asymmetry, and Southern Oscillation Index and the physical characteristics of clouds by calculating normalized cross-correlations, motivated by the idea that the galactic cosmic ray influx modulated by solar activity may cause changes in cloud coverage, and in turn the Earth's climate. Unlike previous studies based on the relative difference, we have employed cloud data as a whole time-series without detrending. We found that the coverage of high-level and low-level cloud is at a maximum when the solar north-south asymmetry is close to the minimum, and one or two years after the solar north-south asymmetry is at a maximum, respectively. The global surface air temperature is at a maximum five years after the solar north-south asymmetry is at a maximum, and the optical depth is at a minimum when the solar north-south asymmetry is at a maximum. We also found that during the descending period of solar activity, the coverage of low-level cloud is at a maximum, and global surface air temperature and cloud optical depth are at a minimum, and that the total column water vapor is at a maximum one or two years after the solar maximum.