• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.29 no.1
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• pp.39-55
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• 1993

Modal Analysis is the process of characterizing the dynamic properties of an elastic structure by identifying its modes of vibration. A mode of vibration is a global property of an elastic structure. That is, a mode has a specific natural frequency and damping factor which can be identified from response data at practically any point on a structure, and it has a characteristic mode shape which identifies the mode spatially over the entire structure. Modal testing is able to be performed on structural and mechanical structure in an effort to learn more about their elastic behavior. Once the dynamic properties of a structure are known its behavior can be predicted and therefore controlled or corrected. Resonant frequencies, damping factors and mode shape data can be used directly by a mechanical designer to pin point weak spots in a structure design, or this data can also be used to confirm or synthesize equations of motion for the elastic structure. These differential equations can be used to simulate structural response to know input forces and to examine the effects of pertubations in the distributed mass, stiffness and damping properties of the structure in more detail. In this paper the measurement of transfer functions in digital form, and the application of digital parameter identification techniques to identify modal parameters from the measured transfer function data are discussed. It is first shown that the transfer matrix, which is a complete dynamic model of an elastic plate structure can be written in terms of the structural modes of vibration. This special mathematical form allows one to identify the complete dynamics of the structure from a much reduced set of test data, and is the essence of the modal approach to identifying the dynamics of a structure. Finally, the application of transfer function models and identification techniques for obtaining modal parameters from the transfer function data are discussed. Characteristics on vibration response of elastic plate structure obtained from the dynamic analysis by Finite Element Method are compared with results of modal analysis.

• Journal of the Korean Society of Costume
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• v.40
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• pp.109-119
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• 1998

In order to identify the factors responsible for the recent drastic increase of imported apparel in Korea, an attempt was made to determine the variables influencing the purchasing behavior of imported and domestic apparel and forecast the purchasing intention with the use of Fishbein & Ajzen's behavioral intention model including both attitude and subjective norm. Based on literature review, the empirical study was conducted using the questionnaire for 900 college women and high school girls living in Seoul. Descriptive statistics, t-test, paired-t test, multiple regression analysis, and correlation analysis were made of 771 returned questionnaires using SAS program. The results were as follows : First, the results of assessing both their attitudes toward imported and domestic apparel and their subjective norms were shown to be different. Second, there was a difference in the attributes that had an effect on their attention to buy imported and domestic apparel. Third, those respondents having a preference for imported apparel were most highly influenced by color and price. While those respondents showing a preference for domestic apparel were most highly influenced by materials and comfortableness. Fourth, the validity of the prediction value of their buying intention was confirmed as it was shown to be more than coreelation coefficien r=0.65. In conclusion, 1) it was proved that both attitude and subjective norm were the important variables that could predict the consumer's purchasing intention, 2) since competitiveness in color and materials and brand influencing the consumer's purchase of and preference for domestic apparel relatively lagged behind in comparison with that of imported apparel, the domestic apparel business enterprise will have to make a greater effort to develop differentiated color, material and prestigious brand so as to enhance competitiveness with imported apparel.

• Journal of Biosystems Engineering
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• v.36 no.6
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• pp.407-415
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• 2011

Damage to agricultural production caused by insects and diseases affects farming yields. The orchard sprayer is mainly used in the country to protect the fruit in a large area, with less effort and at minimum cost. The excellent performance of the air blast spray increases the fruit protection. Chemical application in orchards has been accomplished by the orchard sprayers with air assist nozzles and a axial fan in Korea. However, the orchard sprayers without ROPS resulted in severe injury or death when operators drive the sprayers improperly on hilly orchard or farming road. This study was to develop a ROPS for the orchard sprayers improving farmer's safety. In this study, the accident case was used in analysing the design and building TOP structure of the orchard sprayer. The maximum impact, body torsion frame structures including the driver's protection are also analysed for adherence to safety regulations. The ROPS safety regulations according to the strength test results were established.

• Research in Community and Public Health Nursing
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• v.10 no.2
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• pp.400-411
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• 1999

The purpose of this study was to identify the physical exercise and the effects of exercise on health. Data were collected from Oct. to Dec. 1998. The subjects were 241 middle aged women living in Seoul and near Seoul. The following instruments were used in the study: The questionniare for physical exercise and health status was combined with simple CMI and climacteric symptom. Analysis of the data was done by chi-test. t-test. and ANOVA with SAS program. The results of this study were as follows: 1. The rate of physical exercise was 59.3% of subjects. The mean number of exercise per week was 3.1. Duration at one time exercise was 25.6 minutes. The period of exercise was 18.6 months. And main objective of exercise was health promotion. 2. The physical exercise had differences according to the age. job. monthly income. period of marriage. type of family. and perceived body image. 3. Musculoskeletal and mental complaints were lower in no-exercise group than exercise group(respectively P=0.04. 0.02). According to the duration of exercise. autonomous nervous symptoms was the lowest in 20 minutes group(P=0.04) and psychologic complaints was the lowest in below 60 minutes group(P=0.03). According to the period of exercise. cardiovascular and fatigue complaints was the lowest in 7-12 months maintenance group and autonomous nervous complaint was the lowest in below 3 months maintenance group(P=0.04). This study is only a preliminary effort. so I recommend that the repeated studies be carried out including detailed. comprehensive exercise practice and developing systematic exercise program.

• Research in Community and Public Health Nursing
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• v.22 no.2
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• pp.151-161
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• 2011

Purpose: The purpose of this study was to analyze the effects of a case management program on range of motion, pain, depression and self efficacy in community-dwelling older women with knee arthritis. Methods: The research design was one-group pre and post-test design with 40 participants with knee arthritis who agreed to participate in the 12-week case management program. Data were collected four times, before and after 4, 8 and 12 weeks. Results: Repeated measures ANOVA revealed significant differences between before and after the service in range of motion, pain, depression and self efficacy. Significant improvements from the baseline to 4 weeks after the service were observed in the measurements of range of motion, pain, depression and self efficacy. There were no significant differences in range of motion, pain and depression between 4 and 12 weeks after the services. Conclusion: This study represents the first effort showing that a case management program can have positive outcomes on range of motion, pain, depression and self efficacy for older women with knee arthritis. More research using a control group pre-post test design considering time lapse is needed in order to examine more accurately the effects of case management programs for knee arthritis.

• The Journal of the Korea Contents Association
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• v.14 no.5
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• pp.411-424
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• 2014

This study tries to establish the evaluation standards of the service quality of local cultural festivals in an effort to identify public awareness of those festivals. Also, based on the importance-performance importance-performance analysis on the service quality, this research is aimed at finding ways to enhance service quality and to improve operation plans in more efficient ways for the maximization of visitors' use of festivals. Ultimately, the current study seeks to make a contribution to improving the quality of local cultural festivals. The results of the correspondence t-test analysis of importance and performance revealed that significant differences were found in following items of five factors; 1) in the responsiveness factor, the presence or absence of rest space, facility guide, communication, and installation of public restroom/cleanliness 2) in the certainty factor, food prices and staff members' kindness 3) in the reliability factor, all items including festival pamphlets (to the festival venue), guidance facilities/signposts, hospitality, schedule information, and quick responses 4) in the tangibility factor as well, all items such as the awareness of local culture, benefits, and storytelling 5) in the empathy factor, diversity of events and festival contents.

• Journal of Korean society of Dental Hygiene
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• v.12 no.2
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• pp.355-363
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• 2012

Objectives : The purpose of this study was to examine the influential factors for denture-wearing elderly people's denture satisfaction and subjective oral health and the relationship between the two in an effort to provide some information on the oral health promotion of the elderly. The subjects in this study were 192 senior citizens who were residing in the city of Busan and were wearing denture. Methods : The collected data were analyzed by the statistical package SPSS 18.0. To see whether there would be any differences in subjective oral health awareness according to general characteristics and denture-related characteristics, $x^2$-test was carried out, and t-test or one-way ANOVA involving Duncan post-hoc analysis was utilized to look for any possible gaps in denture satisfaction according to those characteristics. Results : 1. Concerning oral health awareness by general characteristics, there were significant differences according to gender and the form of health insurance subscription. 2. As for subjective oral health awareness by denture-related characteristics, there were significant gaps according to denture-washing frequency. 3. Regarding denture satisfaction by general characteristics, there were significant differences in satisfaction with denture fixation according to living arrangements. 4. As to denture satisfaction by denture-related characteristics, there were significant differences in satisfaction with mastication and with fixation according to the type of denture. 5. Better subjective oral health awareness led to better satisfaction with mastication, better satisfaction with fixation and better aesthetic satisfaction. 6. In relation to subjective oral health awareness and denture satisfaction, that had a significant relationship to satisfaction with mastication and with fixation. Conclusions : The above-mentioned findings showed that the denture satisfaction of the denture-wearing senior citizens was linked to their subjective oral health awareness. Therefore it will be possible to improve denture-wearing elderly people's quality of life when oral health plans geared toward boosting their denture satisfaction are carried out.

• The Journal of the Korea Contents Association
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• v.17 no.4
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• pp.413-423
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• 2017

This study was examined to confirm the mediating effect of ego resilience on the relation between parental neglect and abuse and school life adjustment in adolescents. For this research, this study used the 4th-year data from the Korean Child and Youth Panel Survey(KCYPS)' 4th grader in elementary school and analyzed 2,092 1st grade of middle school students. Data was analyzed by means of descriptive statistics, Pearson coefficient correlation and hierarchical analysis. To examine the mediating effect, the study used sobel test. The findings ]were as follows. First, parental neglect and abuse negatively effected adolescents' school life adjustment. Second, adolescents' ego resilience has a partial mediating effect on the relation between parental neglect and adolescents' school life adjustment. Third, adolescents' ego resilience has a partial mediating effect on the relation between parental abuse and adolescents' school life adjustment. These results suggest that home, school, and local community need to make an effort to improve ego resilience of adolescents, who are suffering from parental neglect and abuse, for school life adjustment.

• Journal of Biosystems Engineering
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• v.17 no.3
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• pp.229-236
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• 1992

In an effort to localize the spray-dryer which is markedly used for drying food materials, a experiment was carried out with a wheel type atomizer locally designed and manufactured to evaluate the effect of rotational speed, feed rate and physical properties of liquid food material on the droplet size, and to develop a model to predict the droplet size sprayed at various operational conditions. The result are summarized as follows. 1. The frequency of droplet size sprayed from the atomizer at every treatment were similar to normal distributions. 2. Under the test conditions adopted in this study, that is, rotational speed of the atomizer ranging from 15,000 to 20,000 rpm (55.0 m/sec - 73.3 m/sec), feed rate from 14 to 37 kg/hr and viscosity of the material from 1.14 to 350 cP, the mean volume-surface dia. of droplets was decreased as increase in rotational speed and was not affected significantly by the feed rate and viscosity. 3. Through the dimensional analysis, a prediction model was developed as follows : $$\frac{Dvs}{r}=K[\frac{Q}{{\mu}r}]^a[\frac{rN^2}{g}]^b[\frac{{\rho}^2r^3g}{{\mu}^2}]^c[\frac{L}{r}]^d$$ and it was proved that the above model was better in degree of fitness than other models reported. 4. A prediction equation for the droplet size sprayed from the atomizer under the test was expressed as follows : $$\frac{Dvs}{r}=0.0215[\frac{Q}{{\mu}r}]^{0.06}[\frac{rN^2}{g}]^{0.3314}[\frac{{\mu}^2}{{\rho}^2r^3g}]^{0.0158}$$.

• Journal of Biosystems Engineering
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• v.39 no.4
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• pp.324-329
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• 2014

Purpose: The finite element method (FEM) is advantageous because it can save time and cost by reducing the number of samples and experiments in the effort to identify design factors. In computational problem-solving it is necessary that the exact material properties are input for achieving a reliable analysis. However, in the case of fiber boards, it is difficult to measure their cross-directional material properties because of their small thickness. In previous research studies, the Poisson's ratio was measured by analyzing ultrasonic wave velocities. Recently, the Poisson's ratio was measured using a high-speed digital camera. In this study, we measured the transverse strain of a fiber board and calculated its Poisson's ratio using a high-speed digital camera in order to apply these estimates to a FEM analysis of a fiber board, a corrugated board, and a corrugated box. Methods: Three different fiber board samples were used in a uniaxial tensile test. The longitudinal strain was measured using the Universal Testing Machine. The transverse strain was measured using an image processing method. To calculate the transverse strain, we acquired images of the fiber board before the test onset and before the fracture occurred. Acquired images were processed using the image processing program MATLAB. After the images were converted from color to binary, we calculated the width of the fiber board. Results: The calculated Poisson's ratio ranged between 0.2968-0.4425 (Machine direction, MD) and 0.1619-0.1751 (Cross machine direction, CD). Conclusions: This study demonstrates that measurement of the transverse properties of a fiber board is possible using image processing methods. Correspondingly, these processing methods could be used to measure material properties that are difficult to measure using conventional measuring methodologies that employ strain gauge extensometers.