• Journal of the Korean Society for Heat Treatment
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• v.6 no.4
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• pp.213-222
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• 1993

This research was performed to investigate the transformation behavior and shape memory effect of Cu-13.5Al-4.5Ni(wt%) alloy with various aging temperature and time. The results obtained in this study are as follows: Transformation temperature was very increased when aging temperature is at $250^{\circ}C$. The variation of transformation temperature in first reverse transformation cycle and second was very significant, but there was little difference in case of 2nd and 3rd. Transformation temperature at various aging temperature was increased with increasing of aging temperature and time. Microvickers hardness was increased with increasing of aging temperature and time. It was found that ${\alpha}$ and ${\gamma}_2$ phase were created by aging of long time at high temperature.

• Journal of Welding and Joining
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• v.12 no.2
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• pp.76-86
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• 1994

Spot welding behavior of galvanized steel has been studied using both numerical and experimental techniques. The model that used to calculate temperature distribution within weldment is two-dimensional axis-symmetric finite difference method, and nugget sizes of specimen welded in condition of welding current and time has been estimated by experiment Results have shown that nugget sizes are increased in proportion to welding current and time, but the growth rate of nugget is decreased. Shear-tensile strength tests have shown interface fracture when welding current is 7, 9KA, welding time is 8-14cycle and 11KA, 8-10cycle respectively, but above 7, 9KA fracture shows button type. In button fracture, shear-tensile strengths have been proportional to nugget sizes.

• Journal of Korea Multimedia Society
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• v.25 no.2
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• pp.421-431
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• 2022

The purpose of this research is to determine the point of fixation of the driver during the process of driving. Based on the results of this research, the driving instructor can make a judgement on what the trainee stare on the most. Traffic accidents have become a serious concern in modern society. Especially, the traffic accidents among unskilled and elderly drivers are at issue. A driver should put attention on the vehicles around, traffic signs, passersby, passengers, road situation and its dashboard. An eye-tracking-based application was developed to analyze the driver's gaze behavior. It is a prototype for real-time eye tracking for monitoring the point of interest of drivers in driving practice. In this study, the driver's attention was measured by capturing the movement of the eyes in real road driving conditions using these tools. As a result, dwelling duration time, entry time and the average of fixation of the eye gaze are leading parameters that could help us prove the idea of this study.

• Journal of ILASS-Korea
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• v.28 no.3
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• pp.113-118
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• 2023

This study investigates the evaporation characteristics of paired sessile droplets on a heated substrate. In particular, the evaporation time and contact line behaviors were analyzed based on the droplet-to-droplet distance and substrate temperature. The contact line behavior and volume variations were visualized using the shadowgraph method. It was observed that the contact diameter and contact angle exhibited similar behavior for both single and paired droplets regardless of the droplet-to-droplet distance and substrate temperature. The paired droplets demonstrated a longer evaporation time than the single droplet due to the vapor accumulation between the droplets. Furthermore, the scaled lifetime, defined as the ratio of evaporation time between paired and single droplets, increased as the droplet-to-droplet distance decreased and decreased as the substrate temperature increased, attributed natural convection.

• Korean Journal of Health Education and Promotion
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• v.20 no.1
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• pp.173-186
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• 2003

The objectives of this study were to verify the determinants of regular exercise behavior in female workers by applying a modified Theory of Planned Behavior. The variables investigated for this study were health status, health concern, health habit, attitude (7 items), subjective norm (3 items), and perceived behavioral control(5 items). Data was collected from 204 female workers using a self-administered questionnaire. The results of this study were as follows. 1) Regular exercise behavior was significantly influenced by perceived behavior control for time, pleasurable attitude, and the subjective norm of their colleagues. 2) A modified Theory of Planned Behavior is particularly useful in explaining exercise behavior of female workers. We suggest that health care providers should focus on not only attitude and social norms but also perceived behavioral control in order to improve the exercise behavior of female workers.

• Journal of the Korean Institute of Educational Facilities
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• v.21 no.6
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• pp.43-54
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• 2014

This study focuses on analyzing children's behavior from an integrated systemic perspective of the space and time and presenting a criterion and a guide of children-centered environmental color for intensifying their behavior affordance while considering functions of the space and color. Research was conducted as follows. Based on the spatial function and children's behavior, it figured out a prerequisite of educational environmental colors for behavior affordance. It extracted colors by dividing children's behavior affordance into 8elements considering a psychology of expectation and color function according to spatial and behavior affordance intensification elements. So 97school colors were selected for children's behavior affordance from abstracted colors by each element. Furthermore, it planned to suggest an environmental color guide for establishing elementary school's positive educational circumstances through enhancing behavior affordance, providing a potential to change a color environment at the educational space.

• Journal of The Korean Dental Society of Anesthesiology
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• v.14 no.1
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• pp.57-62
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• 2014

Background: The aim of this study was to analyze outpatient anesthesia for dental treatment in handicapped patients with behavior disorder in order to use data for carrying out better and safe anesthetic management. Methods: The data were drawn from the 100 patients with behavior disorder who visited CNUDH dental clinic for disabled based on anesthesia record to investigate patient's systemic condition, cooperative level, anesthesia method according to patients cooperation, and side effects after recovery time. Results: Mental retardation (58%) is the most reason to choose general anesthesia. The methods of induction according to cooperative level are intravenous propofol injection in 22 cases and inhalation of sevoflurane in 78 cases. Induction time of anesthesia were within 10 seconds in cases of propofol induction and average $48.8{\pm}18.5$ seconds in cases of inhalation induction. The time spent on dental treatment was average $3.2{\pm}1.1$ hours. After the end of treatment, average time to move from unit chair to recovery bed, to recliner, and to discharge from hospital are $10.4{\pm}5.1$, $36.9{\pm}17.1$ and $72.4{\pm}16.0$ minutes, respectively. During recovery, there are nausea with 9%, vomiting with 4%, dizziness with 2%, finger injury with 1%. Conclusions: This study showed our successful anesthetic outcomes without any severe side effects or complications. Through this study, it will be used for safe anesthetic management as useful reference data.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.29 no.5 s.236
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• pp.633-642
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• 2005

Nucleate pool boiling experiments for R11 under a constant wall temperature condition were carried out. A microscale heater array was used for the heating and the measurement of high temporal and spatial resolution by the Wheatstone bridge circuit. Very sensitive heat flow rate data were obtained by the control for the surface condition with high time resolution. The measured heat flow rate shows a discernable peak at the initial growth stage and reaches an almost constant value. In the thermal growth region, bubble shows a growth proportional to $t^{\frac{1}{5}}$. The bubble growth behavior is analyzed with a dimensionless parameter to compare with the previous results in the same scale. As the wall superheat increases, the departure diameter and the departure time increase, and the waiting time decreases. But the asymptotic growth rate is not affected by the wall superheat change. The effect of the wall superheat is resolved into the suggested growth equation. Dimensionless parameters of time and bubble radius characterize the thermal growth behavior well, irrespective of wall condition. The comparison between the result of this study and the previous results shows a good agreement at the thermal growth region. The quantitative analysis for the heat transfer mechanism is conducted with the measured heat flow rate behavior and the bubble growth behavior. The required heat flow rate for the volume change of the observed bubble is about twice as much as the instantaneous heat flow rate supplied from the wall.

• Journal of the Korean Society of School Health
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• v.29 no.3
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• pp.209-217
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• 2016

Purpose: This study was to examine the changes in knowledge, attitudes, and preventive behaviors among elementary school students after providing them with tuberculosis prevention education. Methods: A total of 235 students from D elementary school in G city were selected. After completing tuberculosis prevention education, the subjects were surveyed five times for 16 weeks. 1,087 samples were included in the final analysis. One-way ANOVA, $Scheff{\acute{e}$'s test, Pearson's correlation, and multiple regression analysis were performed to examine the changes in tuberculosis-related knowledge, attitudes and preventive behaviors over time. Results: After 16 weeks from the education, the scores of preventive behaviors did not show any significant difference compared to the time right after the education. However, the scores of knowledge and attitudes tended to improve. In particular, 1st~2nd graders had high scores in both knowledge and attitude, and the scores of knowledge and attitude gradually increased over time. The correlation between knowledge, attitude, and preventive behavior regarding tuberculosis had a positive significance during the entire time of the survey. Conclusion: Positive associations between knowledge and attitude and between attitude and preventive behavior sustained for 16 weeks after tuberculosis education among elementary school students. This study suggests that tuberculosis prevention education conducted early on from lower grades can produce more educational effects and that it could be a foundation not only for developing knowledge of tuberculosis but also for cultivating adequate attitudes and forming active tuberculosis preventive behaviors.

• Journal of Korean Society of Transportation
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• v.20 no.6
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• pp.129-140
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• 2002

This paper develops a dynamic structural equation model, which captures relationships among socio-demographics, activity participation(i.e., time use) and travel behavior in consideration with time variation effects. The data used in developing the model are two waves(the year 1991 and 1992) from Puget Sound Transportation Panel (PSTP). which is surveyed in Puget Sound Region in United States. The PSTP is widely used in transportation behavior analysis and includes various information of traveler's socio-economic, travel patterns, and activity participation. In the model, we use 10 endogenous variables including activity participations and travel behaviors and 10 exogenous variables composed of time variant and invariant traveler's socio-demographic variables. The empirical model shows that strong relationships exist not only between socio-demographics and travel behavior, but between waves. We also confirm needs of panel data set to identify and understand time variation effects and travel behaviors.