• Journal of the Korean Society for Railway
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• v.15 no.1
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• pp.48-61
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• 2012

It is of great importance to assure the running safety, ride comfort and serviceability in designing the floating slab track for mitigation of train-induced vibration. In this paper, for this, analyzed are the system requirements for the running safety, ride comfort and serviceability, and then, the behavior of train and track at the floating slab track including the transition zone to the conventional concrete slab track according to several main design variables such as system natural frequency, arrangement of spring at transition, spacing of spring isolators, damping ratio and train speed, using the dynamic analysis technique considering the train-track interaction. The results of this study demonstrate that the discontinuity of the support stiffness at the transition results in a drastic increase of the dynamic response such as wheel-rail interaction force, rail bending stress and rail uplift force. Hence, it is efficient to decrease the spacing of springs or to increase the spring constants at the transition to obtain the running safety and serviceability. On the other hand, the vehicle body acceleration as a measure of ride comfort is little affected by the discontinuity of the stiffness at the transition, but by the system tuning frequency; thus, to obtain the ride comfort, it is of great significance to select the appropriate system tuning frequency. In addition, the effects of damping ratio, spacing of springs and train speed on the dynamic behavior of the system have been discussed.

• Korea journal of population studies
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• v.35 no.1
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• pp.181-209
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• 2012

Employment form and gender as stratification factors may generate health disparities in Korea. Previous studies have examined the existence of health disparities by employment form and gender. However, few studies examined how the health disparities can be reduced effectively. This study intends to confirm the existence of health disparities between employment-gender groups and explore the effective health resources which can reduce the possible disparities. Using a national probability sample of Korean adults collected in 2011, we attempts to test the interaction effects between employment-gender groups and health resources on self-rated health. For health resources, 24 variables of five dimensions(social relationship, psychological resource, activity factor, health behavior, and usage of medical service) are taken into account. In results, first, the health levels of the other three employment-gender groups are worse than that of male-regular workers. Second, the effective health resources which can reduce the health disparities are different across the employment-gender groups. An effective health resource for female-nonregular workers is a peaceful relationship with her children. Effective health resources for male-nonregular workers are peaceful relationships with his parents and siblings, low stress, religious activity, and exercise. An effective health resource for female-regular workers is interpersonal trust. These results imply that personal or social interventions for health of specific disadvantaged groups need to focus on specific resources which are more effective for the groups.

• The Journal of Advanced Prosthodontics
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• v.5 no.4
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• pp.471-478
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• 2013

PURPOSE. The aim of the study was to evaluate the effect of annealing on the nanostructure and hardness of Co-Cr metal ceramic samples that were fabricated with a direct metal laser sintering (DMLS) technique. MATERIALS AND METHODS. Five groups of Co-Cr dental alloy samples were manufactured in a rectangular form measuring $4{\times}2{\times}2$ mm. Samples fabricated by a conventional casting technique (Group I) and prefabricated milling blanks (Group II) were examined as conventional technique groups. The DMLS samples were randomly divided into three groups as not annealed (Group III), annealed in argon atmosphere (Group IV), or annealed in oxygen atmosphere (Group V). The nanostructure was examined with the small-angle X-ray scattering method. The Rockwell hardness test was used to measure the hardness changes in each group, and the means and standard deviations were statistically analyzed by one-way ANOVA for comparison of continuous variables and Tukey's HSD test was used for post hoc analysis. P values of <.05 were accepted as statistically significant. RESULTS. The general nanostructures of the samples were composed of small spherical entities stacked atop one another in dendritic form. All groups also displayed different hardness values depending on the manufacturing technique. The annealing procedure and environment directly affected both the nanostructure and hardness of the Co-Cr alloy. Group III exhibited a non-homogeneous structure and increased hardness ($48.16{\pm}3.02$ HRC) because the annealing process was incomplete and the inner stress was not relieved. Annealing in argon atmosphere of Group IV not only relieved the inner stresses but also decreased the hardness ($27.40{\pm}3.98$ HRC). The results of fitting function presented that Group IV was the most homogeneous product as the minimum bilayer thickness was measured (7.11 ${\AA}$). CONCLUSION. After the manufacturing with DMLS technique, annealing in argon atmosphere is an essential process for Co-Cr metal ceramic substructures. The dentists should be familiar with the materials that are used in clinic for prosthodontics treatments.

• Journal of Korean Academy of Nursing
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• v.22 no.4
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• pp.569-588
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• 1992

This study examined the relationship between the experience of stressful life events and somatic symptoms of urban women. Data were collected by interviewing 200 women from June to July 1, 1991. Vsable data work obtained from 162 of the women. Modified version of a stressful life events measurement tool developed p.5. Lee (1984) and the Somatic Discomfort Inventory by Wittenborn were used to measure the variables. Data were processed by an 5.p.5.5. program and analyzed. statistically for percentage, T-test, ANOYA and Pearson Correlation coefficient. Result of the Study are as follows : 1) The group total mean score of stressful life events was 92.66 $\pm$ 10.41. The higher scores in the $\boxDr$Test and school$\boxUl$ of the Extrapersonal factor, in the $\boxDr$Health problems$\boxUl$ of the Intrapersonal factor and $\boxDr$Conflict and differences within the family$\boxUl$ of the Interpersonal factor, factors. which a suggested by Neuman's model. 2) The group total mean score for somatic symptoms was 100.41$\pm$9.74. The higher scores were for the factors of $\boxDr$Fatigue (1.94)$\boxUl$, $\boxDr$Menopause (1.74)$\boxUl$, $\boxDr$Muscular system(1.67)$\boxUl$ and $\boxDr$Sleeping (1.67)$\boxUl$ 3) The mean scores of stressful life events were higher in the 40~60 age group, for middle school graduates(P＜.05), career women and those in nuclear families (P＞.05). 4) The mean scores of somatic symptoms were higher in the 45~60 age group, for middle school graduates, non career women and women with 5 or more children(P＜.05). 5) There was a positive correlation between the scores of stressful life events and somatic symptoms (r＝.585 P＜.05). The higher the level of stressful life events the higher the score of somatic symptoms, the results were consistent with the Extrapersonal, Intrapersonal and Interpersonal stress factors of Neuman's Health Care Systems. This research assessed the stressful life events of women, who play the most important role in the family for illness prevention and health promotion and suggested the importance of programs in the Primary Health Services to build basic coping resources.

• Journal of the Microelectronics and Packaging Society
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• v.14 no.2 s.43
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• pp.49-57
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• 2007

Au-Sn solder alloy were deposited in multilayer and co-sputtered film by rf-magnetron sputter and the composition control and analysis were studied. For the alloy deposition condition, each components of Au or Sn were deposited separately. On the basis of pure Sn and Au deposition, the deposition condition for Au-Sn solder alloy were set up. As variables, the substrate temperature, the rf-power, and the thickness ratio were used for the optimum composition. For multilayer solder alloy, the roughness and the composition of solder alloy were controlled more accurately at the higher substrate temperature. In contrast, for co-sputtered solder, the substrate temperature influenced little to the composition, but the composition could be controlled easily by rf-power. In addition, the co-sputtered solder film mostly consisted of intermetallic compound, which formed during deposition. The compound were confirmed by XRD. Without flux during bonding of solder alloy film on leadframe, the adhesion strength were measured. The maximum shear stress was $330(N/mm^2)$ for multilayer solder with Au 10wt% and $460(N/mm^2)$ for co-sputtered solder with Au 5wt%.

• Sleep Medicine and Psychophysiology
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• v.9 no.1
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• pp.61-67
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• 2002

Objectives: This study is aimed at measuring psychophysiological responses using a biofeedback system in healthy people to obtain basic normative data for biofeedback research and treatment. Methods: Ninety-six healthy volunteers (55 males and 41 females : average age $30.4{\pm}8.0$) without any history of major medical or psychiatric illnesses participated in this study. Psychophysiological responses were assessed using the ProComp+ and BioGraph program (ver. 2.1) with regard to forearm and frontal electromyography (EMG), electrodermal response (EDR), and skin temperature. They were measured in 3 phases (baseline, stress, and recovery phases), respectively. Beck depression inventory and Spielberger state and trait anxiety inventory were used to measure mood states. We compared psychophysiological responses according to age and gender differences, respectively and examined the relationship between mood states and psychophysiological measures. Results: People in their twenties showed higher EDR levels in the 3 phases than those of other age groups. Female subjects showed higher frontal EMG levels in the 3 phases compared with male subjects. There was no significant correlation between biofeedback measures and mood states in these subjects. Conclusion: We present normative data of psychophysiological responses measured by a biofeedback system in healthy people. These results suggest that gender and age should be considered as important variables in assessing psychophysiological responses using a biofeedback system.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.34 no.2
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• pp.153-160
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• 2010

A magnetocardiogram (MCG) is a recording of the biomagnetic signals generated by cardiac electrical activity. Biomagnetic instruments are based on superconducting quantum interference devices (SQUIDs). A liquid cryogenic Dewar flask was used to maintain the superconductors in a superconducting state at a very low temperature (4 K). In this study, the temperature distribution characteristics of the liquid helium in the Dewar flask was investigated. The Dewar flask used in this study has a 30 L liquid helium capacity with a hold time of 5 d. The Dewar flask has two thermal shields rated at 150 and 40 K. The temperatures measured at the end of the thermal shield and calculated from the computer model were compared. This study attempted to minimize the heat transfer rate of the cryogenic Dewar flask using an optimization method about the geometric variable to find the characteristics for the design geometric variables in terms of the stress distribution of the Dewar flask. For thermal and optimization analysis of the structure, the finite element method code ANSYS 10 was used. The computer model used for the cryogenic Dewar flask was useful to predict the temperature distribution for the area less affected by the thermal radiation.

• Journal of Music and Human Behavior
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• v.16 no.2
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• pp.109-132
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• 2019

This study aimed to investigate the relationship between music listening and mood regulation. The effects of personality traits, music education, and sex on music use for mood regulation were also examined. Participants were 529 undergraduate students who completed the Korean Music in Mood Regulation Scale, Interpersonal Personality Item Pool (IPIP), Positive Affect and Negative Affect Schedule, and a questionnaire on their music education. Correlation analysis, multiple regression analysis, and t tests were conducted to explore the relationship among the measured variables. The results showed that music listening was related to enhancement of positive mood but not improvement of negative mood. Participants who had received extracurricular music education were more likely to use music listening as a strategy to regulate their mood than were participants without music education. Women were more likely to use music for mood regulation than were men. The multiple regression results indicate that individuals who rated themselves highly on Agreeableness and Openness to Experience on the IPIP were more likely to listen to music for mood regulation. These findings stress that music listening can be an effective strategy for mood regulation, which is critical for one's emotional well-being. It also indicates that effective music use as a mood regulation strategy varies depending on one's personal characteristics and history of music education.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.11
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• pp.6451-6457
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• 2013

Background and Purpose: Indigenous people who leave their hometowns and move to the city to earn a living became urban aboriginals. During the process of adapting to urban living situations, they may use various coping strategies such as smoking to overcome their stress. Therefore, it is crucial to provide health education including smoking prevention, increasing knowledge regarding of tobacco hazard, self-efficacy of anti-smoking, and adjusting smoking behavior so as to empower their anti-smoking motivation to prevent lung cancer. The purpose of this study was to explore the effectiveness of an anti-smoking program on urban aboriginals in Taiwan. Methods: A quasi-experimental study design with purposeful sampling was employed. A total of 125 aboriginal subjects were recruited from two local churches at Shu Lin area in northern Taiwan. Subjects were divided into an experimental group (n =64 ) and a control group (n = 61). Both took pre-tests in order to set baseline values, and only the experimental group participated for 3-weeks in the anti-smoking program classes. Both groups took post-tests immediately after the intervention in order to evaluate the immediate effects of the teaching program, and a follow-up test was conducted four weeks after the intervention. Data were analyzed using descriptive statistics, one-way ANCOVA, and repeat measure ANCOVA. Results: After controlling for confounding variables, the results showed that there were statistically significant differences in the self-efficacy of anti-smoking and smoking behavior between experimental and control groups in the immediately post-test and the follow-up test (p < 0.05). However, there was no significant differences in the recognition of hazards of smoking at eiter time point. Conclusions and Implications for Practice: The findings of this study revealed that the anti-smoking program effectively improved self-efficacy of anti-smoking, and decreased the smoking behavior in urban aboriginals. They provide useful information as a reference regarding of aboriginal health promotion to health providers. It is imperative that anti-smoking be reinforced for those regular smokers to prevent induction of lung cancer.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.17 no.3
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• pp.319-332
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• 2004

Due to their high strength to weight ratios and excellent durability, fiber reinforced polymer(FRP) is widely used in construction industries. In this paper, a shape optimum design of FRP bridge decks haying pultruded cellular cross-section is presented. In the problem formulation, an objective function is selected to minimize the volumes. The cross-sectional dimensions and material properties of the deck of FRP bridges are used as the design variables. On the other hand, deflection limits in the design code, material failure criteria, buckling load, minimum height, and stress are selected as the design constraints to enhance the structural performance of FRP decks. In order to efficiently treat the optimization process, the cross-sectional shape of bridge decks is assumed to be a tube shape. The optimization process utilizes an improved Genetic Algorithms incorporating indexing technique. For the structural analysis using a three-dimensional finite element, a commercial package(ABAQUS) is used. Using a computer program coded for this study, an example problem is solved and the results are presented with sensitivity analysis. The bridge consists of a deck width of 12.14m and is supported by five 40m long steel girders spaced at 2.5m. The bridge is designed to carry a standard DB-24 truck loading according to the Standard Specifications for Highway Bridges in Korea. Based on the optimum design, viable cross-sectional dimensions for FRP decks, suitable for pultrusion process are proposed.