• Korean Journal of Applied Biomechanics
• /
• v.13 no.3
• /
• pp.27-46
• /
• 2003

The purposes of this study were to determine the functions of actions of the limbs during each of the three support phases of the triple jump and their relationships with the performance of the triple jump. Four elite male triple jumpers were participated as subjects. The statistical analyses used were the Pearson product moment correlation coefficient for establishing relationships and simple regression analyses to determine and compare the relationships between the change of the horizontal velocity and the change of the vertical velocity during different support phases. A level of significance at p<.05 was set. The actions of the arms were responsible for about 25%, 25%, and 30% of the decrease in the horizontal velocity of the whole body center of gravity during the support phases of the hop, step, and jump, respectively. The change in the velocities of the whole body center of gravity due to the actions of the free limbs were significantly related with the whole body center of gravity during each support phase. The action of the support leg was associated with the decrease in the horizontal velocity and the increase in the vertical velocity of the whole body center of gravity during each support phase.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
• /
• 2002.05a
• /
• pp.53-62
• /
• 2002

Condition monitoring plays a vital role since it sustains reliable operation of industrial plants and machinery in the pursuit of economic whole life operation. In order to achieve this goal, it is needed to monitor various parameters of mechanical system such as vibration, wear, temperature and etc., and finally to diagnosis the root causes of any possible abnormal machine condition. In this work, a machine failure caused by mechanical looseness was experimentally simulated and on-line measurement of the vibration, wear and temperature were simultaneously measured. For the quantitative analyses of machine wear, several statistical parameters of the wear particle size distribution were obtained through the center moment method of the Weibull distribution function, and they were compared to vibrational characteristics. Results showed that the wear and vibrational characteristics did not reveal a strong correlation each other in a loosely supported proceeding bearing.

• Journal of Korean Society on Water Environment
• /
• v.24 no.2
• /
• pp.239-246
• /
• 2008

In this study, an optimized deterministic water-quality model was constructed to estimate water quality of a river and lake in the upstream basin of a dam. A stochastic water-quality analysis using reliability analysis technique was applied to the model. The model was tested in the 13.9 km reach from Maeil stage station of Kyechun to Hoengsung Dam of Sum River. After finding hydraulic characteristics from nonuniform flow analysis, Broyden-Fletcher-Goldfarb-Shanno (BFGS) optimization technique for model calibration was applied to determine optimum reaction parameters, and model verification was performed based on these. The stochastic model, using Mean First­Order Second­-Moment (MFOSM) and Monte-Carlo methods, was applied to the same reach as the deterministic study. Variations of discharge and water quality in headwater were considered, as well as variations of hydraulic coefficients and reaction coefficients. The statistical results of output variables from MFOSM were similar to those from the Monte-Carlo method. Risk analysis using MFOSM and Monte-Carlo methods presented the probabilities of some locations in the Hoengsung Lake violating existing water-quality standards in terms of DO and BOD.

• Journal of the Korean Society of Food Culture
• /
• v.12 no.1
• /
• pp.71-78
• /
• 1997

The productivity of a hospital foodservice system has a significant implication in hospital management as costs for labor and material increase, competitions among hospitals increase, and patients' expectations as to the quality of hospital services increase. The foodservice is characterized by its labor intensiveness. The objective of this study was to examine associations between operational and managerial factors and the productivity of dishwashing work in hospital foodservice systems. The labor productivity in 20 conventional food service systems was assessed and related to a number of influencing variables within the system. The productivity measurement was based upon the total dish equivalents as a ratio of the total direct and non-direct labor hours required to wash these dishes. 20 hospitals with more than 500 beds located in Seoul were surveyed to obtain data for study variables. Questionnaire and a survey form were mailed. Statistical methods used in this study were descriptive analysis and Pearson product moment correlation analysis. Hospital system characteristic which was found to correlate significantly with productivity was the ratio of dish loss. As this increased, the productivity level increased.

• The Korean Journal of Community Living Science
• /
• v.21 no.2
• /
• pp.191-200
• /
• 2010

The purpose of this study was to research the differences between gender roles and creativity. This study was done based on 178 pre-service teachers who were from the Department of Early Childhood Education in Universities around the Busan area. The researchers have collected statistical data by questioning pre-service teachers about creative thinking tests, creative personality tests, and gender role identification awareness tests. The data was interpreted by the Paerson's Simple Product-moment Correlation Coefficient method, the one-way ANOVA method, and the $Sch\acute{e}ffe$ Post-hoc comparison method. According to this study, the group perceived of high androgyny type group showed the highest level in important factors of creative thinking, such as fluency, elaborateness, ness, and openness. This result meant that the more a pre-service teacher was aware of the identity of gender roles, the more she or he thought creatively. Additionally, the acceptance of authority, an element of the creative personality factor, showed the highest level in a high feminity type group. On the other hand, self confidence, inquisitiveness, and disciplined imagination showed the highest level in a group which perceived the identity of androgyny type roles.

• Earthquakes and Structures
• /
• v.12 no.1
• /
• pp.109-118
• /
• 2017

A novel post-tensioned self-centering (SC) concrete beam-column connection with web friction devices has been proposed for concrete moment-resisting frames. This paper presents a probabilistic performance evaluation procedure to evaluate the performance of the self-centering concrete frame with the proposed post-tensioned beam-column connections. Two performance limit states, i.e., immediate occupancy (IO) and repairable (RE) limit states, are defined based on peak and residual story drift ratios. Statistical analyses of seismic demands revealed that the dispersion of residual drifts is larger than that of peak drifts. Due to self-centering feature of post-tensioning connections, the SC frame was found to have high probabilities to be recentered under the design basis earthquake (DBE) and maximum considered earthquake (MCE) ground motions. Seismic risk analysis was performed to determine the annual (50-year) probability of exceedance for IO and RE performance limit states, and the results revealed that the design objectives of the SC frame would be met under the proposed performance-based design approach.

• The Bulletin of The Korean Astronomical Society
• /
• v.39 no.2
• /
• pp.83.2-83.2
• /
• 2014

Flare and rotational variabilities induced by stellar activity are important for studying the effect of magnetic fields on the evolution of red dwarf stars. The level and frequency of magnetic activity in these stars have a different aspect at every moment of the observations due to the effect of age-rotation relation. The use of both tracers is thus essential to have a relatively homogeneous set of stellar activity data for statistical studies. The archival light curves and imaging data of the open cluster M37 taken by MMT 6.5m telescope were used for this work. In order to achieve much more accurate photometric precisions and also to make the most efficient use of the data, the entire imaging database were re-analyzed with our new time-series photometry technique and carefully calibration procedures. Based on the new light curves, we study, for the first time, a variety of aspects of those two variabilities in red dwarfs and their relation to magnetic activity. In this talk, we present all observational evidences that support the idea that the strength of magnetic activity is closely connected with the rotation rate of a star and its evolutionary status (age-activity-rotation paradigm). In conclusion, we suggest future directions to improve our understanding of stellar activity in cool stars with photometric time-series data.

• Speech Sciences
• /
• v.12 no.2
• /
• pp.89-99
• /
• 2005

The purpose of the present study were (1) to assess differences in tongue performances and speech intelligibility between normal and dysarthric speakers; and (2) to analyze the possible interrelationships between tongue strength, range of motion, and speech intelligibility in dysarthric patients. In order to measure maximum strength of anterior and lateral tongue strength, a force transducer has been designed. And a ruler was used for guaging range of motion. 'Word intelligibility test' was administered to each group. The results were analyzed by a quantitative statistical method(t test, Pearson product- moment correlation, and one-way ANOVA). The results were as follows; (1) dysarthric speakers showed significantly poorer performance than the normal in the tongue strength, range of motion, and speech intelligibility tasks; (2) the correlation between speech intelligibility and instrumental tongue performance was high in the dysarthric group; and (3) instrumental assessment was coincide with perceptual judgement of dysarthric tongue performance. The present investigation demonstrated that tongue weakness is causally related to articulation deficits in dysarthric. The clinical use of the force transducer would help a speech pathologist to quantify the degree of tongue weakness.

• Journal of the Korea Fashion and Costume Design Association
• /
• v.14 no.2
• /
• pp.33-47
• /
• 2012

The purposes of this study were to investigate the differences of self-efficacy and appearance management behavior according to demographic variables, to disclose the relationship between self-efficacy and appearance management behavior, and to examine the characteristics that affect appearance management behavior of male and female college students. The research method was a survey method using a questionnaire. The subjects were 632 college students (male: 302, female: 330) living in Seoul area. Statistical analysis methods were factor analysis, Cronbach's ${\alpha}$-reliability coefficient, t-test, ${\chi}^2$-test, one-way ANOVA, Duncan's multiple range test, Pearson's product-moment correlation coefficient, and multiple regression analysis. The self-efficacy factor derived four categories including self-control efficacy, social self-efficacy, physical self-efficacy, and task difficulty preference. The college students who were in higher social stratification and older had more appearance management behavior, and those who had lower task difficulty preference and lower physical self-efficacy had more plastic surgery management. Both men and women who had higher self-control efficacy had more clothing management. Women who had higher self-control efficacy, social self-efficacy, and task difficulty preference had more appearance management expenses.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.14 no.5
• /
• pp.1043-1053
• /
• 1994

This study suggests a practical but rational approach for the development of reliability-based LRFD criteria for transmission towers under wind and ice loadings in Korea. Based on available statistical data on wind speed and icing on transmission lines in Korea, the design wind and ice loads are obtained by Monte Carlo Simulations. In the study, the AFOSM reliability method and an Importance Sampling Technique are used for the element and system reliability evaluation of actual transmission towers. Based on the selected target reliabilities, a set of load and resistance factors for the LRFD criteria are calibrated using the AFOSM and the code optimization technique.