• Korean Journal of Health Education and Promotion
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• v.19 no.3
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• pp.51-72
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• 2002

This research was conducted to understand and analyze the health-related behaviors of middle school students and get fundamental research data essential to provide efficient student guidance and public health service at school. The interview using Youth Risk Behavior Surveillance System(YRBSS). Translation and modification for Korean students of the YRBS. The Korean version of YRBS(Youth Risk Behavior Surveillance System) that translation and modification for Korean students of the YRBS developed by the Centers for Disease Control and Prevention(CDC)was used to assessment to health-related behaviors of youth. The interviewees were 1040 enrolled students at middle school in Daegu metropolitan city. YRBSS monitors six categories of priority health behaviors among youth and young adults behaviors that contribute to unintentional and intentional injuries; tobacco use; alcohol and other drug use, sexual behaviors that contribute to unintended pregnancy and sexually transmitted diseases(STDs)(including human immunodeficiency virus infection); unhealthy dietary behaviors; and physical activity. The result shows that over 30% of students rarely or never used safety belt and almost students were rarely or never wore a bicycle helmet. During the 12 months preceding the survey, 21.9% female students had felt so sad or hopeless almost every day for $\geq$ 2weeks in a row that they stopped doing some usually activities 20.5% of male middle school students have ever tried cigarette smoking. 26.2% of male students and 27.2% do female students had had over one drinks of alcohol during their lifetime(lifetime alcohol use). 47% of male students had had over one drinks of alcohol on $\geq$ 1 of the 30 days preceding the survey(current alcohol use). Over one half of female student were thought they were overweight. These results suggest that some risk behaviors be very prevalent in a korean middle school students and priority health-risk behaviors, which contribute to the leading cause of mortality and morbidity among youth and adult, often are establish during middle school age, extend into adulthood, are interrelated. Among both children and adults, the leading causes of death are closely linked to these behaviors. Among adults, chronic diseases such as cardiovascular disease, cancer, and diabetes are the national leading killers. Practicing healthy behaviors, such as eating low-fat, high-fruit-and-vegetable diets, getting regular physical activity, and refraining from tobacco use, would prevent many premature deaths. Because health-related behaviors are usually established in childhood, positive choices need to be promoted before damaging behaviors are initiated or become ingrained.

• Proceedings of the KWS Conference
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• 2002.10a
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• pp.600-605
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• 2002

The keyhole formed by high energy density laser-material interaction periodically collapses due to surface tension of the molten metal in partial penetration welds. The collapse sometimes traps a void at the bottom of the keyhole, and it remains as welding defects. This phenomenon is seen as one cause of the instability of the keyhole during laser beam welding. Thus, it seems likely that improving the stability of the keyhole can reduce voids and uniform the penetration depth. The goal of this work is to develop techniques for controlling laser weld keyhole dynamics to reduce weld defects such as voids and inconsistent penetration. Statistical analysis of the penetration depth signals in glycerin determined that keyhole dynamics are chaotic. The chaotic nature of keyhole fluctuations and the ability of laser power modulation to control them have been demonstrated by high-speed video images of laser welds in glycerin. Additionally, an incident leading beam angle is applied to enhance the stability of the keyhole. The quasi-sinusoidal laser beam power of 400Hz frequency and 15$^{\circ}$ incident leading beam angle were determined to be the optimum parameters for the reduction of voids. Finally, chaos analyses of uncontrolled signals and controlled signals were done to show the effectiveness of modulation on the keyhole dynamics. Three-dimensional phase plots for uncontrolled system and controlled system are produced to demonstrate that the chaotic keyhole dynamics is converted to regular periodic behavior by control methods: power modulation and incident leading beam angle.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.34 no.5
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• pp.382-385
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• 2021

Electrical poling is a crucial step to convert ferroelectrics to piezoelectrics. Nevertheless, no systematic investigation on the effect of poling has been reported. Given that the poling involves an alignment of spontaneous polarization, the condition for poling should be different when a material has an internal bias field that influences the domain stability. Here, we present the effect of poling profile on the dielectric and piezoelectric properties in Mn-doped Pb(Mg_1/3Nb_2/3)O₃-29 mol%PbTiO₃ single crystal with an internal bias field. We showed that both the dielectric permittivity and the piezoelectric coefficient were further enhanced when the poling procedure ends with a field application along the opposite direction to the internal bias field. We expect that the current finding would give a clue to understanding the true mechanism for the electrical poling.

• Advances in Computational Design
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• v.2 no.2
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• pp.107-119
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• 2017

The Micro circular diaphragm (MCD) is the mechanical actuator part used in the micro electro-mechanical sensors (MEMS) that combine electrical and mechanical components. These actuators are working under harsh mechanical and thermal conditions, so it is very important to study the mechanical and thermal behaviors of these actuators, in order to do with its function successfully. The objective of this paper is to determine the thermo-mechanical behavior of MCD by developing the traditional bulge test technique to achieve the aims of this work. The specimen is first pre-stressed to ensure that is no initial deflection before applied the loads on diaphragm and then clamped between two plates, a differential pressure (P) and temperature ($T_b$) is leading to a deformation of the MCD. Analytical formulation of developed bulge test technique for MCD thermo-mechanical characterization was established with taking in-to account effect of the residual strength from pre-stressed loading. These makes the plane-strain bulge test ideal for studying the mechanical and thermal behavior of diaphragm in both the elastic and plastic regimes. The differential specimen thickness due to bulge effect to describe the mechanical behavior, and the temperature effect on the MCD material properties to study the thermal behavior under deformation were discussed. A finite element model (FEM) can be extended to apply for investigating the reliability of the proposed bulge test of MCD and compare between the FEM results and another one from analytical calculus. The results show that, the good convergence between the finite element model and analytical model.

• The Research Journal of the Costume Culture
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• v.14 no.5
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• pp.850-863
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• 2006

The purpose of this study was to investigate if star marketing of on-line shopping malls affects consumers' WOM effect, and to compare the differences of consumption behavior between female teenagers and college students. Two hundred five female teenagers and college students who had purchased fashion goods through internet shopping mall participated in this study. For data analysis, descriptive statistics, factor analysis, t-test, and multiple regression were used. As the results, first, recognition of celebrity advertising models was classified into three factors such as 'trust of product', 'attractiveness of product' and 'leading interest of product' factors. Second, the greater exposure to celebrity models, the greater the good feelings about them, showing respondents' positive consumption behavior. Third, results of multiple regression revealed that behavior of pursuing celebrities' style accounted for 37% of the explained variance WOM behavior. Finally, t-test revealed that female college students were affected more by celebrity style and bought fashion items than female teenagers. However, female teenagers conducted more WOM behavior than college students. Based on these results, on-line fashion marketers would use these data for more their efficient fashion marketing strategies.

• Journal of Korean Society for Quality Management
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• v.50 no.2
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• pp.251-264
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• 2022

Purpose: This study aims to contribute to the research flow on the relationship between win-win supportive collaboration and safety, while noting that win-win supportive collaboration affects corporate safety-related factors such as climate, safety prevention, and behavior from the perspective of domestic small and medium-sized logistics companies that have signed contracts with large logistics companies, Methods: Based on responses from 147 small and medium-sized logistics companies, structural equation modeling is performed to examine the relationship among the factors such as supportive collaboration, safety climate, safety prevention, safety behavior. Results: Study results are as follows. Supportive collaboration of large logistics companies influence the formation of a safety climate and safety behavior within logistics SMEs positively. In addition, safety prevention and safety behavior are affected by safety climate in a positive way. Conclusion: Win-Win supportive collaboration is a driving force behind safety management practices in the supply chain leading to safety management performance, so it is necessary to consider it for the growth of the sustainable supply chain.

• International Journal of Contents
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• v.13 no.1
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• pp.76-85
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• 2017

This paper compares the difference in the degree of advertising avoidance between traditional media and the Internet. The study also examines customers' beliefs, attitudes, and behavior toward advertising to build a theoretical model that explains advertising avoidance. A survey was conducted to identify the influential factors. Findings indicate that on comparison, YouTube advertisements on the Internet were more problematic than TV commercial breaks, leading to high advertising avoidance on the part of consumers. Finally, using path analysis, a general advertising avoidance model based on the belief-attitude-behavior hierarchy is tested. The model shows that certain beliefs about advertising have direct effects on advertising avoidance behavior as well as on the attitude toward advertising.

• Proceedings of the KSME Conference
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• 2002.08a
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• pp.503-506
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• 2002

Electrorheological fluids(ERFs) show a rapid and reversible increase in viscosity by applied electric field. It is called the electrorheological effect (ER effect). The reason for ER effect is the induction of an electric dipole in each particle, leading to the formation of clusters in the direction of the field, which resist fluid flow. Generally, the behavior of ER fluids has been modeled on those of Bingham fluids. But there are some differences between Bingham fluids and ER fluids. The visualization of ER fliuds are presented and ER effects by the forming, growing and breaking of clusters are discussed. In the low shear rate area, the pressure drop is measured by a pressure sensor and the formation of ER particles is visualized by video camera. The reason for the nonlinear behavior of ER fluids at low shear rate is explained through results of visualization.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.29 no.3
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• pp.87-95
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• 2006

In this paper, an approach for analyzing brand loyalty and brand switching behavior in car insurance market is presented. A two-choice model by Blumen, et al. that uses Markov chain is adopted as a main technique for estimating brand parameters. Survey data have been collected through personal interviews with questionnaires. Following the application of the model to the data, it is found that there are five leading companies in car insurance market where the number of potential brand switchers is larger than that of brand loyal customers. Therefore, differentiation of this product along with the conversion of this low-involvement product to a high-involvement one could make car insurance stand out against a somewhat undifferentiated field of competitors.

• Proceedings of the Korean Vacuum Society Conference
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• 2012.02a
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• pp.244-244
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• 2012

Polymer memory devices have attracted considerable attention because of their advantages such as low cost potential, good scalability, flexibility, simplicity in structure, and large capacity for data storage. Metal/poly (4,4'-aminotriphenylene hexafluoroisopropylidenediphthalimide) (6F-TPA PI)/metal system has been found to show an electrical bi-stable behavior. Here, we show a novel set-up of 6F-TPA PI/Al sample in which holes are injected by photoelectron emission process instead of direct charge carrier injection via metal electrode. In this process, an irreversible electrical phase transition of 6F-TPA PI is found, leading to a write-once-read-many (WORM) behavior. The photoelectron spectroscopy results measured before and after the switching process revealed that the irreversible electrical phase transition of 6F-TPA PI is attributed to the chemical modification of the carbonyl group in phthalimide moiety.