• Korean Journal of Child Studies
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• v.38 no.2
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• pp.119-132
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• 2017

Objective: This study aimed to examine the longitudinal relations of children's temperamental attributes (i.e., emotionality, activity, and sociability) and maternal responsiveness to overall and specific externalizing/internalizing behavior problems during the preschool period. Methods: Data (N=1,438) from the 4th and 6th wave of Panel Study on Korean Children (PSKC) were used in a series of hierarchical regression analyses. The analyses were conducted to determine the additive and interactive effects of maternal responsiveness and temperamental attributes of children at the age of 3 years on the broadband and narrowband scales of their behavior problems at the age of 5 years. Results: Overall, results confirmed the additive and interactive effects of maternal responsiveness and temperamental attributes on the levels of different domains of behavior problems. Examination of the interactive effects showed that maternal responsiveness was more strongly related to some behavior problems for temperamentally vulnerable children as compared to children with less temperamental vulnerabilities. Conclusion: The findings suggested that the beneficial effects of positive parenting on the development of behavior problems might be more pronounced for temperamentally vulnerable than for less vulnerable children.

• Proceedings of the KIEE Conference
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• 2003.07e
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• pp.75-78
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• 2003

Energy distribution function for electrons in $SF_6$-Ar mixtures gas used by MCS-BEq algorithm has been analysed over the E/N range $30\sim300$[Td] by a two term Boltzmann equation and by a Monte Carlo Simulation using a set of electron cross sections determined by other authors, experimentally the electron swarm parameters for 0.2[%] and 0.5[%] $SF_6$-Ar mixtures were measured by time-of-flight(TOF) method. The results show that the deduced electron drift velocities, the electron ionization or attachment coefficients, longitudinal and transverse diffusion coefficients and mean energy agree reasonably well with theoretical for a rang of E/N values. The transport coefficients for electrons in (0.2[%])$SF_6$-Ar and (0.5[%]$SF_6$ - Ar mixtures were measured by time-of-flight method, and the electron energy distribution function and the parameters of the velocity and the diffusion were determined by the variation of the collision cross-sections with energy. The results obtained from Boltzmann equation method and Monte Carlo simulation have been compared with present and previously obtained data and respective set of electron collision cross sections of the molecules.

• Journal of Institute of Control, Robotics and Systems
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• v.21 no.9
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• pp.818-826
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• 2015

This paper presents a novel methodology for estimating vehicle ego-motion, i.e. tri-axis linear velocities and angular velocities by using stereo vision sensor and 2G1Y sensor (longitudinal acceleration, lateral acceleration, and yaw rate). The estimated ego-motion information can be utilized to predict future ego-path and improve the accuracy of 3D coordinate of obstacle by compensating for disturbance from vehicle movement representatively for collision avoidance system. For the purpose of incorporating vehicle dynamic characteristics into ego-motion estimation, the state evolution model of Kalman filter has been augmented with lateral vehicle dynamics and the vanishing point estimation has been also taken into account because the optical flow radiates from a vanishing point which might be varied due to vehicle pitch motion. Experimental results based on real-world data have shown the effectiveness of the proposed methodology in view of accuracy.

• Journal of East-West Nursing Research
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• v.17 no.1
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• pp.16-23
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• 2011

Purpose: As anger may be strongly related to stroke, this study examined the relationship between anger expression style (anger-in, anger-out, anger-control) and risk factors for stroke to investigate the possible attribution of anger expression style to stroke incidence. Methods: The cross sectional study design was employed. The 291 participants signed consent forms and completed questionnaires including the anger expression style scales and risk factors for stroke. Data were analyzed using descriptive statistics, t-test and One-way ANOVA. Results: The highest score among anger expression styles of the participants was from anger-control. Participants with higher mean value of anger-out were current non-smokers, doing regular exercise, having scores above 23 in Body Mass Index, having scores above 90 cm (male) or 80 cm (female) in abdominal circumference, and having scores below 85 mmHg in diastolic blood pressure. Participants with more than 5 risk factors to stroke had the highest score of anger-in. Conclusion: The results of this study implied anger expression style was psychological risk factor for stroke. Further studies to differentiate the anger expression style contributing to the risk of stroke are needed with a longitudinal study design.

• International Journal of Aeronautical and Space Sciences
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• v.8 no.1
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• pp.32-45
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• 2007

The T-50 advanced supersonic jet trainer employs the Relaxed Static Stability (RSS) concept to improve the aerodynamic performance while the flight control system stabilizes the unstable aircraft and provides adequate handling qualities. The T-50 flight control laws employ a proportional-plus-integral type controller based on a dynamic inversion method in longitudinal axis and a proportional type controller based on a blended roll system with simple roll rate feedback and beta-betadot feedback system. These control laws are verified by flight tests with various maneuver set flight envelopes and the control laws are updated to resolve flight test issues. This paper describes several concepts of flight control laws used in T-50 to resolve those flight test issues. Control laws for solving the roll-off problem during pitch maneuver in asymmetric loading configurations, improving the departure resistance in negative angle of attack conditions and enhancing the fine tracking performance in air-to-air tracking maneuvers are described with flight test data.

• The Korean Journal of Community Living Science
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• v.24 no.1
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• pp.119-132
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• 2013

This study aims to understand potential gender differences in the association between job characteristics and job satisfaction among older workers. The data are from 506 males and 202 females older than 55 from the first wave of the Korean Longitudinal Study of Ageing(KLoSA). Analyses focused on examining gender differences in the influences of subjective evaluation of work characteristics measured with education and skill fits of the work, work demands, customary early retirement, as well as more objective job conditions assessed with insurances by the employer, work hours, and salary on job satisfaction. Regression analyses revealed that female workers showed higher job satisfaction while job characteristics worked differently between genders to affect job satisfaction. For males, fitting the job with education and job demands were determining factors of job satisfaction, while the job with skills and work hours appeared to be significant factors for females. Results suggest that opportunities to utilize older workers' human capital and flexible working hours, especially for females workers would be helpful in promoting older adults' employment and satisfaction about their work.

• The Korean Journal of Community Living Science
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• v.24 no.1
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• pp.37-49
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• 2013

The purpose of this study is to explore how health and health behavior factors moderate the relation between socio-economic position(SEP) and Korean elderly people's self-rated health status. The data sources are from the Korean Longitudinal Study of Aging(2008). The analysis sample consists of 4,040 cases. Analysis of the results shows that health characteristics such as ADL, MMSE, geriatric depression, and pain are significant predictors of self-rated health status. In addition, exercise and drinking alcohol also prove to be factors influencing self-rated health status. Health factor such as MMSE and health behavior factors such as drinking alcohol served as moderators of the influences of SEP on one's self-rated health status. For example, higher MMSE provides a slight increase to the positive relationship between SEP and self-rated health status. In addition, those who responded yes to drinking alcohol, compared to those who responded no, provides an increase to the positive relationship between SEP and one's self-rated health status.

• Proceedings of the Korean Society For Composite Materials Conference
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• 2005.11a
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• pp.95-98
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• 2005

This paper proposes the solutions predicting the coefficient of the thermal expansion changes of composites which include the fiber-like shaped ($a_1$ > ($a_2$ = ($a_3$) and the disk-like shaped (al = a2> a3) inclusions like two dimensional geometries, which has one aspect ratios, ${\alpha}$ = ($a_1$ /($a_3$). The analysis follows the procedure developed for elastic moduli by using the generalized approach of Eshelby’s equivalent tensor. The influences of the aspect ratios, on the effective coefficient of thermal expansion of composites containing aligned isotropic inclusions are examined. This model should be limited to analyze the composites with unidirectionally aligned inclusions and with complete binding to each other of both matrix and inclusions having homogeneous properties. The coefficient of thermal expansion of composites (${\theta}_{11}$,${\theta}_{22}$and ${\theta}_{33}$) are investigated. From material data of the composites with glass fiber in epoxy resin, the thermal expansions along the aspect ratio were obtained and similar to the Chow model. The longitudinal coefficients of thermal expansion ${\theta}_{11}$decrease, as the aspect ratios increase. However, the transverse coefficients of thermal expansion ${\theta}_{22}$increase or decrease, as the aspect ratios increase. And both of them decrease, as the concentration increases.

• Journal of Mechanical Science and Technology
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• v.19 no.9
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• pp.1801-1810
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• 2005

The effect of longitudinal thin rectangular riblets aligned with the flow direction on turbulent channel flow has been investigated using direct numerical simulation. The thin riblets have been modeled using the immersed boundary method (IBM) where the velocities at only one set of vertical nodes at the riblets positions are enforced to be zeros. Different spacings, ranging between 11 and 43 wall units, have been simulated aiming at getting the optimum spacing corresponding to the maximum drag reduction while keeping the height/spacing ratio at 0.5. Reynolds number based on the friction velocity ${\mu}_\tau$ and the channel half depth $\delta$ is set to 150. The flow is driven by adjusted pressure gradient so that the mass flow rate is kept constant in all the simulations. This study shows similar trend of the drag ratio to that of the experiments at the different spacings. Also, this research provides an optimum spacing of around 17 wall units leading to maximum drag reduction as experimental data. Explanation of drag increasing/decreasing mechanism is highlighted.

• The Mathematical Education
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• v.50 no.1
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• pp.103-118
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• 2011

The study examined whether the relation between mathematics self-efficacy and mathematics achievement was partially mediated by the learning strategies, using latent growth model analyses. It was also examined the auto-regressive, cross-lagged (ARCL) panel model for testing the stability and change in the relation of mathematics self-efficacy and learning strategy over time. The study analyzed the first-year to the third-year data of the Korean Educational Longitudinal Survey (KELS). The result of ARCL panel model analysis showed that earlier mathematics self-efficacy could predict later learning strategy use. There were linear trends in mathematics self-efficacy, learning strategy, and mathematics achievement. Specifically, mathematics achievement was increased over the three time points, whereas mathematics self-efficacy and learning strategies were significantly decreased. In the analyses of latent growth models, the mediating effects of learning strategies were overall supported. That is, both of initial status and change rate of rehearsal strategy partially mediated the relation of mathematics self-efficacy and mathematics achievement. However, in elaboration and meta-cognitive strategies, only the initial status of each variable showed the indirect relationship.