• Journal of the Korean Society for Precision Engineering
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• v.23 no.6 s.183
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• pp.128-135
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• 2006

Rational dynamic modeling and analysis method f3r complex structures are studied with special attention to slide way joints. For modeling of slide way joints, a general modeling technique is used by using the influence coefficients method which is applied to the conversion of detailed finite element model to the equivalent reduced joint model. The theoretical part of this method is illustrated and the method is applied to the structure with slide way joint. In this method, the non-linearity of the contact surfaces is considered within a proper range and the boundary effect of the joint model could be eliminated. The proposed method was applied to finite element modal analysis of a clamp jointed cantilever beam and slide way joints of the vertical type lathe. The method can also be used to other kinds of joint modeling. The results of these analysis were compared with those of Yoshimura models and rigid joint models, which demonstrated the practical applicability of the proposed method.

• Wind and Structures
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• v.16 no.1
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• pp.93-115
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• 2013

This paper describes a study of the influence of a dynamically flexible building structure on pressures inside and net pressures on the roof of low-rise buildings with a dominant opening. It is shown that dynamic interaction between the flexible roof and the internal pressure results in a coupled system that is similar to a two-degree-of-freedom mechanical system consisting of two mass-spring-damper systems with excitation forces acting on both the masses. Two resonant modes are present, the natural frequencies of which can readily be obtained from the model. As observed with quasi-static building flexibility, the effect of increased dynamic flexibility is to reduce the first natural frequency as well as the corresponding peak value of the admittance, the latter being the result of increased damping effects. Consequently, it is found that the internal and net roof pressure fluctuations (RMS coefficients) are also reduced with dynamic flexibility. This model has been validated from experiments conducted using a cylindrical model with a leeward end flexible diaphragm, whereby good match between predicted and measured natural frequencies, and trends in peak admittances and RMS responses with flexibility, were obtained. Furthermore, since significant differences exist between internal and net roof pressure responses obtained from the dynamic flexibility model and those obtained from the quasi-static flexibility model, it is concluded that the quasi-static flexibility assumption may not be applicable to dynamically flexible buildings. Additionally, since sensitivity analyses reveal that the responses are sensitive to both the opening loss coefficient and the roof damping ratio, careful estimates should therefore be made to these parameters first, if predictions from such models are to have significance to real buildings.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.7
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• pp.555-561
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• 2019

This study analyzed the shipbuilding structure of House Tangerine over a ten day period and according to the month in Jeju. By estimating and analyzing the price flexibility function of House Tangerine, the aim was to determine if the shipment control can stabilize and increase the incomes of House Tangerine farmers and derive policy implications. The greatest decline in the coefficients of the ten-day price flexibility occurred in the equations from early June to late July. Therefore, the shipment control of House Tangerine is required more during early June and late July. The coefficient of DUM_Q, indicating the year in which the quality of House Tangerine is somewhat deteriorated, was statistically significant and had a (-) sign. The coefficients of DUM_SUK, indicating the year in which Chuseok (Korean Thanksgiving Day) was in October, was statistically significant and had a (-) sign in the middle and late October. The greatest decline in the coefficient of monthly price flexibility function occurred in July, June, and September. Therefore, shipment control is required more in July, June, and September. The (-) signs of the coefficients of DUM_Q and DUM_SUK suggest that the need for shipment control is more important when the quality is less than better quality and that the necessity of shipment control is required more when Chuseok is in October, respectively.

• Journal of muscle and joint health
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• v.10 no.2
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• pp.131-141
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• 2003

The purpose of this study was to examine the effects of self-help program on patients with chronic arthritis. This study was performed from 13th of August to 29th of October 2002. 30 arthritis patients with an average age of 56 years were participated in the self-help program. At the completion of 6 weeks, 23 patients completed both pretest and posttest, overall dropout rate was 23%. Outcome measures were status of daily living, self-care activities, flexibility, grip strength and depression. Data were analysed by percentage, paired t-test, Pearson's correlation coefficient. There were statistically significant in self-care activities, flexibility, grip strength after the self-help program. However no significant differences were found in daily living and depression. There were significant relationships between daily living and depression. There were significant relationships between right flexibility & left flexibility and right and left grip strength. In conclusion self-help program was proved to be an effective nursing intervention to increase the self-care activities, flexibility and grip strength. These results of this study suggested that the follow-up program after the self-help program should be run to help the physical psychological wellbeing of arthritis patients.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.20 no.4
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• pp.80-86
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• 2021

Plastics are widely used in mechanical and other fields due to their light weight, design flexibility, and molding processability. In processing plastics, defective products are mixed and reprocessed to improve production efficiency and reduce costs. In this study, an experiment was conducted to confirm the coefficient of thermal expansion of HDPE during this reprocessing. The coefficient of thermal expansion was measured at different measurement directions and heating rates. As a result, we observed that the coefficient of thermal expansion in the direction perpendicular to the injection direction is greater than that in the horizontal direction.

• Wind and Structures
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• v.16 no.1
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• pp.61-91
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• 2013

An analytical model of internal pressure response of a leaky and quasi-statically flexible building with a dominant opening is provided by including the effect of the envelope external pressure fluctuations on the roof, in addition to the fluctuating external pressure at the dominant opening. Wind tunnel experiments involving a flexible roof and different building porosities were carried out to validate the analytical predictions. While the effect of envelope flexibility is shown to lower the Helmholtz frequency of the building volume-opening combination, the lowering of the resonant peak in the internal and net roof pressure coefficient spectra is attributed to the increased damping in the system due to inherent background leakage and envelope flexibility. The extent of the damping effects of "skin" flexibility and background leakage in moderating the internal and net pressure response under high wind conditions is quantified using the linearized admittance functions developed. Analytical examples provided for different combinations of background leakage and envelope flexibility show that alleviation of internal and net pressure fluctuations due to these factors by as much as 40 and 15% respectively is possible compared to that for a nominally sealed rigid building of the same internal volume and opening size.

• Journal of the Korean Society of Clothing and Textiles
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• v.34 no.2
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• pp.280-290
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• 2010

This study identifies the antecedents of trust in the examination of the effects of the antecedents of trust on trust in apparel manufacturer-contractor relationships. A total of 92 apparel manufactures participated in this study. A factor analysis, Cronbach's alpha coefficient, and multiple regression analysis were conducted for the statistical analysis. Five antecedents of trust were classified: flexibility, opportunistic behavior, communication, specific investment, reputation. Two factors of trust were identified: credibility and benevolence. Flexibility, communication, and reputation of a contractor positively influenced the credibility of an apparel manufacture in a contractor. Flexibility, communication, and specific investment of a contractor positively relate to the benevolence of an apparel manufacture in a contractor. However, the opportunistic behavior of a contractor did not relate to either the credibility of an apparel manufacture or the benevolence in a contractor. The results of this study provide empirical evidence of the impact of flexibility, communication, specific investment, reputation on trust in apparel manufacturer-contractor relationships, and additional insight for selecting contractors that seek to improve trust in apparel manufacturer-contractor relationships.

• Journal of Home Health Care Nursing
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• v.28 no.3
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• pp.223-232
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• 2021

Purpose: This study aims to examine the effects of occupational stress, coping flexibility, and hardiness on burnout in nurses and the factors influencing these relationships. Methods: Convenience sampling was used in this study to engage a total of 122 nurses from two general hospitals. A structured questionnaire was used to assess the nurses' occupational stress, coping flexibility, hardiness, and burnout. The collected data were analyzed with regard to descriptive statistics, t-test, ANOVA, Pearson's correlation coefficient, and multiple regression by using the SPSS program. Results: There were differences in the extent of burnout in nurses depending on their age, marital status, educational level, and religion. Burnout and occupational stress were positively correlated, whereas there was a negative correlation between burnout and hardiness. For the factors influencing nurses' burnout, occupational stress was identified to be most influential, followed by hardiness, total clinical career, religion, and working unit. Conclusion: To decrease burnout in nurses, there is a need for developing and deploying programs which can reduce their occupational stress and enhance hardiness.

• Journal of Korean Public Health Nursing
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• v.18 no.1
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• pp.167-177
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• 2004

This study was performed to explore the effects of aqua-exercise program on back pain, flexibility. time of exercise and self-efficacy in the women with chronic back pain. The design of this study was a equivalent pre-post test experiment. The subjects consisted of 31 women living in seoul. They underwent tests of back pain. flexibility. time of exercise and self-efficacy as baseline data before aqua-exercise program. The aquatic exercise was based on the Back hab and was consists of 60minutes session, 2 times a week for 5 weeks. Data were analyzed with percentage, mean, standard deviation, t-test and pearson correlation coefficient using SAS program. The results were as follows. 1. The back pain has significantly decreased after aqua-exercise program. 2. The dorsal flexibility has significantly increased after aqua-exercise program. 3. The time of exercise has significantly increased after aqua-exercise program. 3. The Self-efficacy has significantly increased after aqua-exercise program. The findings showed the aqua-exercise program could be effective in decreasing the back pain and effective in increasing the flexibility, time of exercise and self-efficacy. It can be suggested the aqua-exercise is effective in the health promotion of the women with chronic back pain.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2003.06a
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• pp.814-819
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• 2003

Machine tool design concepts have evolved towards high efficiency, accurate precision. high structural integrity, and multi-functional systems. Like many other structures, machine tools are also composed of many parts. When these parts are assembled, many kinds of joints are used. In the finite element analysis of these assembled structures, most joints are commonly considered as rigid joints. But, to get the more accurate solution, we need to model these joints in a appropriate manner. In this study, rational dynamic modeling and analysis method for complex structures are studied with special attention to slide way joints. For modeling of slide way joints, a general modeling technique is used by influence coefficients method which is applied to the conversion of detailed finite element model to the equivalent reduced joint model. The theoretical part of this method is illustrated and the method is applied to the structure with slide way joint. In this method. the non-linearity of the contact surfaces is considered within a proper range and the boundary effect of the joint model can be eliminated. The proposed method was applied to finite element modal analysis of a clamp jointed cantilever beam and slide way joints of the vertical type lathe. The method can also be used to other kinds of joint modeling. The results of these analysis were compared with those of Yoshimura models and rigid joint models. which demonstrated the practical applicability of the proposed method.