• Composites Research
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• v.32 no.6
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• pp.307-313
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• 2019

Triboelectric nanogenerators (TENGs), which are combined effects of triboelectricity and electric induction, is a large-area and low-cost technology that can be applied easily in our life. In this work, we applied life supplies to TENGs and analyzed a type of chemical bonding with the ratio of C-C/C-H/C-O/C=O bonding. As the ratio of C-C bonding increases, the materials can be positively charge. On the other hands, as the ratio of C-H bonding increases, the materials can be negatively charged materials. Based on these behaviors, we got a voltage of 210V, a current of 14.6 ㎂ and a maximum power of 9.8mW. Finally, we could turn on 97 light emitting diodes (LEDs) by using a wrap as a negative material and a magnetic note as a positive material.

• The Korean Journal of Community Living Science
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• v.25 no.1
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• pp.19-27
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• 2014

This study investigates drinking attitudes and behaviors of university students. The sample included 355 students living in Busan, Korea. The questionnaire addressed general background information (gender, age, grade and monthly pocket money), drinking attitudes (understanding the effects of alcohol on the body, stereotype of drink, age at the first drink, the drinking companion at the first drink, reasons for starting to drink, main drinking companions, major reasons for drinking, the history of drinking alone, and reasons for drinking alone), drinking behaviors (the cost of each drinking occasion, drinking amounts, the frequency of drinking, the frequency of heavy drinking, the type of alcoholic beverage, and the places of drinking). A few respondents (both male and female students) started drinking while in high school (p<0.05), and most respondents drank with friends (males: 91.0%, female: 92.2%). The main reasons for drinking were the mood for male student (46.3%) and relationships for female student (49.1%) (p<0.05). Male respondents consumed more than seven glasses of soju (39.9%), whereas female respondents, five to seven glasses (49.7%) (p<0.05). On average, the respondents drank one to two times a week (males: 47.9%, females: 51.5%) and experienced heavy drinking one to three times every three months (males: 19.1%, females: 21.0%) (p<.05). The results suggest that students with frequent alcohol consumption and heavy alcohol dependence are likely to face problems and thus require aggressive intervention strategies that target them specifically.

• Journal of Korean Society of Transportation
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• v.25 no.5
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• pp.209-231
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• 2007

This paper suggested an approach to characterize travel choice behaviors using the implicit price instead of the indirect utility. The choice criterion to compare the implicit prices of available trip options was developed from the utility maximization problem of a trip maker which is supposed to choose the best option from the available ones differentiated by only by the quantitative attributes such as travel cost and time but also by qualitative attributes such as comfort and safety. The utility maximization problem is constructed under household production theory, and is incorporated with a special kind of joint homogeneous production functions. The implicit price of a certain trip option is the sum of the monetary price and the multiple of travel time and the value-of-travel-time, and the value-of-travel-time refers to the portion of wage, which can be assignable to the trip-making activity. This choice criterion is statistically identifiable, and behaviorally plausible. Moreover, this criterion has the expression simpler than the indirect utility, and therefore could be an effective target of the statistical estimation for travel choice behaviors.

• The Journal of Korean Society for School & Community Health Education
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• v.14 no.3
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• pp.89-99
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• 2013

Objectives: This study was designed to examine the effects of oral health behaviors and use of dental clinics on periodontal diseases in women, the purpose of this study is to provide basic information to develop program for dental health promotion in young women. Methods: We conducted a survey targeting 486 women that agreed with the survey and were going to dental clinic from October 1, 2013 to October 18, 2013. We surveyed them by self-administered questionnaire and analyzed it by SPSS Win 19.0 program. Results: 1. For differences in periodontitis according to general characteristics, if th age is high, ratio of periodontitis is high. Married woman is higher than single one in ratio of periodontitis. Also the more number of birth, the higher ratio of periodontitis is.(p<.05) 2. For differences of periodontitis by dental care behavior, ratio of periodontitis of non-smokers is significantly low. For one that brush one's teeth broadside, the ratio of periodontitis is high.(p<.05) 3. For differences of periodontitis by use of dental clinic service, ratio of periodontitis of one that have more times visit to a dental clinic, more annual average cost for dental care, and regular dental check-ups is relatively low.(p<.05). 4. For determinant factors influencing on periodontitis, ratio of periodontitis of one that is old, have more stress, have a low level of education, and have preventive dental care is high. Ratio of periodontitis of one that have less toothbrushing and brush one's teeth after having lunch or a snack and before sleeping is significantly low. Conclusions: From this study, dental health behavior as the factor influencing on periodontitis of young women is statistically meaningful. Because this dental health behavior has a lot of potential to be improved by government and local community efforts such as education and social support, we think that systematic and various educational program development is needed to strengthen self dental care ability effectively with policy support.

• Korean Journal of Community Nutrition
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• v.16 no.3
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• pp.386-397
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• 2011

This study was to investigate the housewives' purchase behaviors on the environment-friendly agricultural products (EFAP) by survey in Daejeon area housewives. 390 questionnaires were used and analysed. Most of the subjects were female (92.6%) distributed evenly in their 40's (55.4%), and graduated from high school (43.6%) or college (36.4%). Subjects' occupation was most housewives (64.1%) and 77.4% of the subjects had monthly family income of 2 million won or more. 76.9% of the subjects had purchased EFAP already. The reason of purchasing EFAP was mainly "good for health" (80.3%), and reason for non-purchasing was "high prices" (28%) or "not so trustworthy" (25.6%). The most purchasing frequency was "once a week" (29%). 46.7% of the subjects spent 20% of their agricultural product cost for EFAP and 38.7% of them spent less than 30,000 won per month for EFAP. On checking of EFAP labeling, the housewives scored 3.59 for the validate date, 3.25 for the place of origin, 2.8 for the quality certification mark by 4-point Likert scale. 65.1% of the subject had intention to increase purchasing of EFAP in future. To promote the consumption of EFAP, the improvement factors were price-cutting (47.9%), trust on producers (18.2%) and quality betterment (17.7%). Accordingly, the consumers prefer EFAP for wellbeing health of families; however, they hesitate to buy due to their high price and the low reliability on producers of EFAP. Thus the producers and the related organization of EFAP should contrive proper countermeasures to increase consumer's satisfaction level on their credibility and price of EFAP.

• The Research Journal of the Costume Culture
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• v.25 no.6
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• pp.804-818
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• 2017

The purpose of this study was to examine the differences of the information searches and purchasing behavior Korean men in their 20s and 30s, focusing on cosmetic involvement. Research methods consisted of qualitative and quantitative approaches. For the qualitative approach, in-depth interviews and participant observations were conducted to investigate male customers' cosmetic characteristics in information searches and purchasing behavior. Then, the study conducted a quantitative study methodology based on the questionnaires from the in-depth interviews, participant observations, and literature review. The study surveyed 340 Korean men in their 20s and 30s. The cosmetic involvement of the target group was classified into the amusing high-involvement group, the rational low-involvement group, and the obligatory high-involvement group. The results from this study indicated that the groups of male customers classified by cosmetic involvement showed statistically significant differences in terms of information searches and purchasing behaviors. Especially, the obligatory high-involvement group generally displayed high-involvement traits likewise the amusing high-involvement, was more similar to the rational low-involvement group regarding cost effectiveness than the obligatory high-involvement group. Moreover, the classifications of men generally had different characteristics of cosmetic purchasing behavior and information searches than women. This study has a distinctive significance compared with other studies in discovering differences of cosmetic purchasing behaviors of Korean men in their 20s and 30s' cosmetic involvement groups classified using qualitative and quantitative approaches.

• Journal of the Society of Naval Architects of Korea
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• v.35 no.1
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• pp.88-97
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• 1998

Large aluminium extrusions can be used in rolling stocks and high speed vessels to reduce weight and labor cost. As sandwich plates with corrugated core have enough strength in transverse and longitudinal direction, welding lines to connect members are reduced and transverse members to strength longitudinal members are not required. However, for proper design of aluminium extrusion plates, understanding of structural behaviors of the exclusions are necessary. In this paper, at first, detailed finite element analysis is carried out to understand structural behavior. And then, simple theoretical formulas for design purpose are proposed using the orthotropic plate theory. Shear stresses resulting from end twisting which is characteristics of deep aluminium extrusion plates can also be calculated by the simple theoretical formula. Comparison with the results by detailed finite element analysis shows good accuracy of the proposed simple formulas. The simple formulas can be useful in repetitive analysis in the initial design stage.

• The Journal of Advanced Prosthodontics
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• v.4 no.4
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• pp.218-226
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• 2012

PURPOSE. The purpose of this study was to propose finite element (FE) modeling methods for predicting stress distributions on teeth and mandible under chewing action. MATERIALS AND METHODS. For FE model generation, CT images of skull were translated into 3D FE models, and static analysis was performed considering linear material behaviors and nonlinear geometrical effect. To find out proper boundary and loading conditions, parametric studies were performed with various areas and directions of restraints and loading. The loading directions are prescribed to be same as direction of masseter muscle, which was referred from anatomy chart and CT image. From the analysis, strain and stress distributions of teeth and mandible were obtained and compared with experimental data for model validation. RESULTS. As a result of FE analysis, the optimized boundary condition was chosen such that 8 teeth were fixed in all directions and condyloid process was fixed in all directions except for forward and backward directions. Also, fixing a part of mandible in a lateral direction, where medial pterygoid muscle was attached, gave the more proper analytical results. Loading was prescribed in a same direction as masseter muscle. The tendency of strain distributions between the teeth predicted from the proposed model were compared with experimental results and showed good agreements. CONCLUSION. This study proposes cost efficient FE modeling method for predicting stress distributions on teeth and mandible under chewing action. The proposed modeling method is validated with experimental data and can further be used to evaluate structural safety of dental prosthesis.

• Journal of the Korean Institute of Gas
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• v.23 no.4
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• pp.65-73
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• 2019

A spiral steel pipe has been more used widely as a structural member as well as transport pipeline because the pipe can be manufactured continuously, consequently more economical than the conventional UOE pipe. As improved pipe manufacture technology makes spiral pipes to have high strength and to have larger diameters, the spiral pipes have been recently used as long distance transport pipeline with a large diameter and strain-based design is thus required to keep structural integrity and cost effectiveness of the spiral pipe. However, design codes of spiral pipe have not been completely established yet, and structural behaviors of a spiral pipe are not clearly understood for strain-based design. In this paper, the effects of residual stresses due to the spiral pipe manufacture process are investigated on the flexural behavior of the spiral pipe. Finite element analyses were conducted to estimate residual stresses due to the manufacturing process for the pipes which have different forming angle, thickness, and strength, respectively. After that, the results were used as initial conditions for flexural analysis of the pipe to numerically investigate its flexural behaviors.

• The Korean Journal of Franchise Management
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• v.13 no.1
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• pp.47-57
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• 2022

Purpose: Recently, it is common to see cases where an amount similar to the cost of a meal is spent on dessert, or an amount greater than the cost of a meal is spent on dessert. The generation MZ is showing a tendency of 'value consumption' by consuming values and beliefs in consideration of the recent impact on society and the environment. Therefore, this study aims to analyze the effect of dessert cafe quality and eco-friendly behavior on customer trust and loyalty targeting the generation MZ who have visited desert cafés. This study examined the mediating role of customer trust in the relationships between desert café quality, eco-friendly behavior and customer loyalty, and also the moderating effect of and eco-friendly behavior on customer trust and customer loyalty. Research design, data, and methodology: To achieve purposes of this study, 229 data were collected from respondents who visited desert café and analyzed using measurement model (reliability test and correlation analysis), Fornell-Larcker Criterion and Heterotrait-Monotrait Ratio (HTMT) assessment, and structural equation model (PLS-SEM) with SPSS 22.0 and SmartPLS 3.3.7. Results: The research results are as follows. First, desert cafes' quality positively influenced customer trust but did not customer loyalty. Second, desert cafes' eco-friendly behavior positively influenced customer trust and customer loyalty. Fourth, the interaction term of dessert cafe quality and eco-friendly behavior did not influence customer trust and customer loyalty. Conclusions: This study emphasized the necessity of service quality and eco-friendly behavior of dessert cafes by examining the relationship between the quality of dessert cafes and eco-friendly behaviors, customer trust and loyalty. It also found the importance of the role of trust in securing loyal customers. In order to secure and retain loyal customers, the owners of dessert cafes should make effortsto improve the quality of the cafes' products and services so that customers can feel a sense of trust, and actively publicize that they are practicing eco-friendly management. As a result of this study, it is intended to provide practical implications for the management of dessert cafes by understand ing the effects of product and service quality and eco-friendly behaviors of companies to bakery industry workers and start-ups.