• Journal of the korean Society of Automotive Engineers
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• v.11 no.1
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• pp.51-56
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• 1989

This study was performed to investigate the effect of defect on fatigue strength under the stress of rotary bending. The specimens were made of low carbon steel having artificial microholes, namely, single micro-hole and two adjacent micro-holes as natural defects, and the effects of the diameter of hole and the distance between the holes on fatigue strength have been investigated. The obtained result can be summarized as follows: 1, The critical defect means the largest size of defect that does not affect fatigue limit, and correspondes to the size of defect leading to final fracture under fatigue limit of smooth specimen. The size of defect which has an effect on fatigue limit is larger than that of critical defect. 2, The defect larger than the critical defect affects fatigue strength for as a kind of size effect, and the physical meaning of size effect of defect is considered same as the one of notch effect.

• Journal of Korean Ophthalmic Optics Society
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• v.20 no.2
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• pp.201-210
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• 2015

Purpose: In order to aggregate effect of the improvement of binocular vision function by vision therapy, total mean effect size, mean effect size by dependent variables, and effect size by characteristics of the subjects and characteristics of treatment were analyzed by meta-analysis. Methods: We analyzed data from 14 Korean National primary studies, which reported effects of vision therapy programs, using meta-analysis. Results: The effect size of total mean was 1.207, which showed high effect. The mean effect size according to the subcategory of the binocular dysfunctions was the highest for vergence dysfunctions group (2.989), followed by accommodative dysfunctions group (0.868) and group with both vergence dysfunctions and accommodative dysfunctions (0.692). The effect size according to the characteristics of the subjects was the highest in the vision therapy conducted in the binocular dysfunctions group (2.509) that had no other dysfunctions. The mean effect size according to the number of programs was the highest (2.310) for 7 times a week. Vision therapy for improving the binocular functions was the most effective (2.019) in 8 weeks later from vision therapy start. Conclusions: It can prove that the therapy for the improvement of binocular vision function is effective through that each result of the vision therapy effect is converted to mean effect size, and being objectifying the mean effect size.

• Journal of Korean Society of Rural Planning
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• v.27 no.4
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• pp.97-107
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• 2021

The purpose of this study is to systematically review and to objectively identify the effect size in order to understand the effects of horticultural therapy on cognitive function, depression, self-esteem, and activity daily living(ADL) of dementia patients. Related studies published in Korean and English were selected by searching domestic and foreign academic databases. The risk of bias assessment of individual studies was performed on the included 18 literatures. Horticultural therapy was found to be significantly effective in cognitive function(effect size=1.06), depression(effect size=0.64), self-esteem(effect size=0.99), and ADL(effect size=1.98) in dementia care. It is expected that related experimental studies will be repeatedly conducted to produce a more objective effect size calculation.

• Journal of Korean society of Dental Hygiene
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• v.22 no.4
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• pp.259-272
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• 2022

Objectives: To identify the factors influencing the turnover intention of registered South Korean dental hygienists and analyze the effect sizes. Methods: Overall, 54 studies based on criteria of PICO from 1 January 2000 to 11 January 2022 were extracted. The factors related to turnover intention were applied to the ecological system theory and categorized. Subsequently, the effect size of the correlations was comprehensively meta-analyzed by dividing it into protective and risk factors depending on the negative or positive correlation direction. Results: For the overall effect size, the protective factor (ES_r=-0.458) was higher than the risk factor (ES_r=0.352). In the protective factors, organizational commitment and perceived organizational support belonging to the microsystem yielded the largest effect size. Furthermore, as for risk factors, burnout, job stress, work harassment, role conflict, and emotional labor belonging to the microsystem showed a moderate effect size. Conclusions: Factors belonging to the microsystem demonstrated a large effect size in both protection and risk factors for dental hygienists' turnover intention. Additionally, the factor showing the largest effect size was protective factor categorized into a microsystem.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.11
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• pp.38-52
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• 2018

This study examined the effect sizes of psychological burnout-related factors on the psychological burnout of early childhood teachers by applying meta - analysis focusing on master 's theses, doctoral dissertations and journals that have been published in Korea for the past 20 years. The results of the analysis are as follows. First, the total effect size, the factor group, the sub-factor, and the positive and negative effect factors of the inducing and inhibiting factors showed a significant effect size. Second, in terms of inducing factors, the task problem group showed a larger effect size than the negative relationship group. Third, among the lower factor of the negative relationship group, all the sub factors excluding the negative relationship with the director, effect size showed a medium effect size. Fourth, task stress showed the greatest effect size among the sub factors of the task factor group, followed by role conflict, task overload, and role ambiguity. Fifth, resilience showed the greatest effect size among the inhibition factors, followed by organizational support factor, teacher efficacy factor, social support factor, and emotional factor. Sixth, all sub factors of the emotional labor factor group, organizational support factor of the organizational support factor group, general teacher efficacy factor of the teacher efficacy factor group, and all sub factors of social support factor Medium effect size. In addition, the lower factor of all the other factors showed a large effect size. Seventh, of the effect factors, job satisfaction factor, depression factor, and turnover intention factor all showed a large effect size.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.11
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• pp.455-464
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• 2020

This study examined the correlation between the variables related to the organizational commitment of social workers. The research results are as follows. First, the overall effect size of the variable group had an intermediate effect size. Among the four organizational commitment-related variables, the job-related negative variable had the largest effect size. Next, the group of positive variables related to the organization, the group of positive variables related to the job, and the group of individuals related to the individual were in order. Second, among the individual-related variables, experience, gender, and education showed a small effect size, and other factors were close to the small effect size. In the group of positive variables related to organization, all variables except for transactional leadership and organizational fairness, which had a medium effect size, showed a large effect size. The job-related positive variables showed a large effect size only for job satisfaction, and customer orientation and job suitability were close to the large effect size. The turnover intention, which is a group of job-related negative variables, had a large effect size and job stress showed a medium effect size.

• Journal of The Korean Society of Integrative Medicine
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• v.7 no.3
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• pp.71-83
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• 2019

Purpose: This meta-analysis aimed to analyze to the effects of aquatic exercise programs in children with cerebral palsy and identify directions for future research. Methods: A systematic search based on the PRISMA guidelines was undertaken for studies conducted between 2006 and 2018 on aquatic exercise programs in children with cerebral palsy. A total of 10 studies were selected according to the inclusion criteria. The methodological quality was assessed using the Risk of Bias Tool for Randomized Controlled Trials (RoB) and Risk-of-Bias Assessment Tool for Non-randomized Studies (RoBANS). A meta-analysis software (CMA 3.0) was used to calculate the mean effect size, effect size by intervention (Halliwick and Watsu Aquatic methods), and effect size by outcome. Results: The mean effect size was 0.457. The effect size by intervention was largest for the Halliwick method, followed by the Watsu method. The effect size by outcome was largest for range of motion, followed by the gross motor function measure, the Pediatric Berg Balance Scale, and the Modified Ashworth Scale. Meta-regression analysis showed effect size increased when sample size, number of sessions, and length of sessions increased. Conclusion: The results show that aquatic exercise programs have a positive effect on children with cerebral palsy. Therefore, it is necessary to develop a guideline that recommends the appropriate intervention and the identifies the direction of future studies on aquatic exercise programs.

• Magazine of the Korea Concrete Institute
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• v.2 no.1
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• pp.91-100
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• 1990

In most of the structural members with initial cracks(or initial notches), the strength tends to decmase as the member size increases. This phenomenon is known as size effect. Among the structural materials of glass, metal or concrete, etc., concrete represents the size effect even without initial crack. According to the previous size effect law, the concrete mem¬ber of very large size can resist little stress. Actually, however, even the large size member can resist some stress if there is no initial crack made artificially, consequently showing a rather milder strength reduction compared to the severe strength reduction by tbe previously derived size effect law. In this study, the theoretical size effect law previously derived by Z.P. Bazant was discussed based on nonlinear fracture mechanics of concrete structures With dissimilar initial cracks, and the prediction models are proposed by regression analysis with the existing test data of more large size speciments for splitting tensile strength, shear strength and uniaxial compressive strength tests.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2000.05a
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• pp.995-1000
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• 2000

In this paper. a mechanistic model is first constructed to predict three-dimensional cutting forces, and the uncut chip th thickness is calculated by following the movements of the position of the center of a cutter, which varies with the nominal feed, cutter deflection and runout. For general implementation to a real machining, this paper presents the method that determines constant cutting force coefficients, irrespective of the cutting conditions or cutter rotation angles. In addition, this study presents the approach which estimates runout-related parameters. the runout offset and its location angle, using only one measurement of cutting forces. For more accurate cutting force predictions, the size effect has to be considered in the cutting force model. In this paper, two approximate methods are suggested since the strict approach is practically impossible due to a measurement problem. The size effect is individually considered for narrow and wide cuts.

• Journal of the Korean Society for Precision Engineering
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• v.25 no.6
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• pp.116-125
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• 2008

In general, fretting is a contact damage process due to micro-slip associated with small amplitude oscillatory movement between two surfaces in contact. Previous studies in fretting fatigue have observed a contact size effect related to contact width. The volume-averaging method of theoretically predicted contact stress fields was required to emulate experimental trends and to predict the observed contact size effects. This contact size effect is captured by the mean values of stresses and strains at the element integration points of FE model and two critical plane models (SWT, FS) in the present paper. It is shown that crack nucleation and fretting fatigue life can be predicted by the FE-based critical plane models.