• Journal of Welding and Joining
• /
• v.15 no.6
• /
• pp.66-77
• /
• 1997

In the present work, Taguchi method for electron beam welding(EBW) process in AISI 4130 steel plate has been adopted for investigating the contribution of effect of welding variables. $A L_8(2^7)$ orthogonal array is adopted to obtain the effect of adjustment parameters. The adjustment parameters consist of accelerating voltage, beam current, travel speed and focus currrent. And the quality features selected for the EBW process are bead width of weldment, reinforcement, penetration depth, undercut and area of weld metal. Variance analysis is performed in order to check the effect of adjustment parameters on EBW. The mechanical properties of electron beam welded joints for each heat treatment conditions are investigated in comparison with those of base metal, especially from the view point of tensile and impact properties.

• Korean Journal of Child Studies
• /
• v.37 no.1
• /
• pp.37-48
• /
• 2016

Objective: To prevent adolescent drinking and smoking, this study proposed a strategy based on the ecological perspective. Methods: The study applied multilevel moderated logistic regression analysis on nationally representative individual-level (2,046 9th grade adolescents) and neighborhood-level (92 geographic areas) data. Results: There was a positive association between risky neighborhood environments (e.g., rate of smoking, drinking, and presence of saloon/bars accommodation) and rates of adolescent drinking and smoking. Furthermore, the interplay between risky neighborhood environments and school adjustment pointed to a possible protective effect of a high level of school adjustment in predicting smoking and drinking among adolescents. Conclusion: Findings highlighted the importance of considering multiple neighborhood social contexts surrounding adolescents to understand their risky behavior. Furthermore, positive intervention strategies that focus on adolescents' positive development within the school domain may act to protect adolescents from harmful neighborhood environments.

• Journal of Korean Society for Quality Management
• /
• v.33 no.1
• /
• pp.22-31
• /
• 2005

With the common objective to improve process productivity and product quality, statistical process control (SPC) and engineering process control (EPC) have been widely used in the discrete-parts industry and the process industry, respectively. The major focus of SPC is on process monitoring, while that of EPC is on process adjustment. The emergence of the hybrid industry necessitates a synergistic combination of the two methods for an effective process control. This paper investigates the existing studies on SPC, EPC, and the integration of the two methods. This paper also presents future research issues in this field.

• Human Ecology Research
• /
• v.56 no.2
• /
• pp.145-156
• /
• 2018

This study investigates the effects of over-parenting behavior and peer-alienation on adolescents' school adjustment and explores the mediating effects of smartphone dependency on the above relations. The subjects were 1,882 first grade students in middle school selected from the 7th year data of the 2010 Korea Children and Youth Panel Survey (2010 KCYPS). Data were analyzed by descriptive statistics, Pearson's correlation, structural equational models, and Sobel test with SPSS 21.0 and Amos 18.0. The findings were as follows. First, there was no significant difference in the school adjustment according to gender. However, boys were higher in the perception of over-parenting behavior and peer-alienation, and girls were higher in smartphone dependency. Second, peer-alienation and smartphone dependency had negative impacts on the school adjustment. But over-parenting behavior had no significant effect on school adjustment. Third, smartphone dependency played a mediator role between over-parenting behavior and peer-alienation as well as the school adjustment. Fourth, there were no significant differences between boys and girls in the relations among over-parenting behavior, peer-alienation, smartphone dependency and school adjustment. But there was a slight difference in influence. The findings of this study suggest that interventions on how to use smartphone correctly are important for improving adolescents' school adjustment. In addition, gender differences in school adjustment should be considered for a better understanding.

• Journal of Families and Better Life
• /
• v.32 no.4
• /
• pp.57-74
• /
• 2014

The purpose of this study is to find which variable has the biggest effect on the school life adjustment of elementary school students among family strength, self-esteem, and the mother's rearing attitude. Second, the study observes how the elementary school student's self-esteem has a moderating effect regarding the rearing attitudes of their mothers and their school life adjustment. Five hundred forty-five fifth and sixth graders from an elementary school in Cheonan, are the participants of this study. The key research findings of this study are as follows: First, among the rearing attitudes of the mothers, family strength, and self-esteem, the variable that showed the greatest relationship with positive school life adjustment was family strength followed by self-esteem. Second, The self-esteem of the elementary school students showed a 1% moderating significant effect between the rearing attitudes of the mothers and school life adjustment. In the high self-esteem group of elementary school students, the moderating effect of self-esteem showed a higher level of school life adjustment when the students perceived that their mother had an affectionate rearing attitude, but showed a lower level of school life adjustment if they perceived their mother's rearing attitude as rejective or overprotective. Therefore, this study suggests that a focus on increasing self-esteem and family strength along with the affectionate rearing attitude of mothers is needed for the positive adjustment of elementary school students.

• Proceedings of the Optical Society of Korea Conference
• /
• 2008.07a
• /
• pp.119-120
• /
• 2008

A HMD type multi-focus 3D display system is developed and proof about satisfaction of eye accommodation is tested. Four LEDs(Light Emitting Diode) and a DMD are used to generate four parallax images at single eye and any mechanical part is not included in this system. The multi-focus means the ability of monocular depth cue to various depth levels. By achieving multi-focus function, we developed a 3D display system for only one eye, which can satisfy the accommodation to displayed virtual objects within defined depth. We could achieve a result that focus adjustment is possible at 5 step depths in sequence within 2m depth for only one eye. Additionally, the change level of burring depending on the focusing depth is tested by captured photos and moving pictures of video camera and several subjects. And the HMD type multi-focus 3D display can be applied to a monocular 3D display and monocular AR 3D display.

• Journal of Families and Better Life
• /
• v.28 no.4
• /
• pp.67-76
• /
• 2010

This study investigates working parent stress. This study surveyed 240 working mothers who are raising toddlers and 106 teachers in Seoul, Cyeong-gi, and Incheon. For this study, the Parenting Stress scale developed by Kim & Kang (1997) was used as the instruments for measurement and parental stress. To measure maternal separation anxiety, this study used the Maternal Separation Anxiety Scale (MSAS) developed by Hock (1989), while the Attitude for Occupation scale developed by Farel (1980) was used to measure the attitude for occupation. In addition, the Preschool Adjustment Questionnaire (PAQ) developed by Jewsuwan, Luster and Kostelink (1992), and modified by Oh Chong Eun (2001) were used as the instruments for measurement and adjustment. Data analysis was done using the SPSS WIN 15.0 version and the collected data were subject to a descriptive statistical analysis, one-way ANOVA t-test, and multiple regression analysis. The influential independent variables affecting parenting stress listed in order of significance were maternal attitude for occupation, adjustment of children, maternal anxiety, and income.

• Journal of Families and Better Life
• /
• v.27 no.2
• /
• pp.305-316
• /
• 2009

The purpose of this study was to investigate how children from low-income families perceived their family strength, ego-resilience and school adjustment. The relative magnitude of effects of family strength, ego-resilience and school adjustment were compared. Data were collected from 217 children in grade 4 through 6 who were attending local child welfare centers located in Seoul, Korea. The key research findings were as follows. Ego-resilience and perceived family strength were related to school adjustment among children in poverty. The relatively greater effect of ego-resilience implied that programs for children in poverty need to focus on developing interpersonal relationship skills or coping strategies designed to enable children from disadvantaged environments to deal with stressful events and to promote their ego-resilience. Additionally, the recovery or enhancement of family strength and ego-resilience will be effective at protecting and solving various adaptive problems that children from low-income families may experience at school.

• Journal of Families and Better Life
• /
• v.26 no.2
• /
• pp.57-70
• /
• 2008

The focus of this study was finding out the relations among resilience of children separated from parents, child rearing factors and socio-emotional adjustment in Korean and Yanbian Korean-Chinese regions. Subjects were elementary school $5{\sim}6$ graders separated from their parents(184 in Korea and 81 in Yanbian). Data analysis was by Pearson's r, F-test and t-test. Resilience of Korean-Chinese children was higher than that of Korean children. Caregivers' child rearing behavioral factor than other child rearing factors was significant for children's resilience, and especially for Korean children, caregivers' child rearing psychological factor -efficacy and stress variables- were meaningful. Socio-emotional adjustment was significantly different between resilience high and low groups in both regions. Implications are that regional differences, caregivers' psychological and behavioral child rearing factors should be considered in supporting the development of children's resilience and socio-emotional adjustment.

• Journal of Institute of Control, Robotics and Systems
• /
• v.16 no.11
• /
• pp.1082-1088
• /
• 2010

In this paper, we propose a new gel-type biomimetic variable-focus lens system. The miniaturization of conventional lens system is limited due to the use of a set of glass lenses for adjusting the focal length. Biologically inspired by the focus adjustment mechanism of the human eye, a gel-type single lens system with variable-focus is presented. The proposed system consists of a gel-type lens, mechanical parts such as body, rotation ring, and winding-type SMA actuator. In addition, the proposed system is designed to operate with a simple and miniaturized mechanical structure using a new attachment and driving mechanism. The focusing performance of the proposed system is verified through a series of experiments and measurements of the shape of the lens using tomography.