• Journal of the Korea Concrete Institute
• /
• v.27 no.6
• /
• pp.615-623
• /
• 2015

The previous strut-and-tie models (STMs) to evaluate the shear strength of squat shear walls with aspect ratio less than 2.0 do not consider the axial load transfer of concrete strut and individual shear transfer contribution of horizontal and vertical shear reinforcing bars in the web. To overcome the limitation of the existing models, a simple STM was established based on the crack band theory of concrete fracture mechanics. The equivalent effective width of concrete strut having a stress relief strip was determined from the neutral axis depth and effective factor of concrete strength. The shear transfer mechanism of shear reinforcement at the extended crack band zone was calculated from an internally statically indeterminate truss system. The shear transfer capacity of concrete strut and shear reinforcement was then driven using the energy equilibrium in the stress relief strip and crack band zone. The shear strength predictions of squat shear walls evaluated from the current models are in better agreement with 150 test results than those determined from STMs proposed by Siao and Hwang et al. Furthermore, the proposed STM gives consistent agreement with the observed trend of the shear strength of shear walls against different parameters.

• Journal of Digital Convergence
• /
• v.19 no.12
• /
• pp.413-425
• /
• 2021

This study examines the motivation for using YouTube 'mukbang' content by integrating the use and satisfaction approach and the technology acceptance model, and identified the determinants that affect the continuous use intention. A survey was conducted on 358 YouTube 'mukbang' content users, and major results were derived through exploratory/confirmatory factor analysis and path analysis using the SPSS 21.0 program and the AMOS 21.0 program. The main results are presented as follows. First, information seeking motive, stress relief motive, and time spending motive had a positive effect on perceived usefulness, and information seeking motive and time spending motive had a positive effect on perceived ease of use. Second, information seeking motivation, stress relief motivation, and time spending motivate had a positive effect on perceived enjoyment and perceived novelty. Third, perceived enjoyment did not have a significant effect on perceived usefulness. Fourth, both perceived enjoyment and perceived novelty had a positive effect on continuous use intention. Fifth, perceived ease of use had a positive effect on perceived usefulness, and perceived ease of use and perceived usefulness had a positive effect on continuous use intention. This study will have academic significance in that it elaborates a model that can identify the continuous use of YouTube 'mukbang' content by integrating the uses and gratifications approach, and technology acceptance model. Future follow-up studies should contribute to the refinement of models related to the determinants of the intention to continue using YouTube's 'mukbang' content through an attempt to integrate various models.

• Journal of Korea Entertainment Industry Association
• /
• v.15 no.2
• /
• pp.111-121
• /
• 2021

This study was conducted with the elderly who used a senior welfare center to help their health improvement. After the status of body composition, senior fitness, life habits, and nutrition levels in the elderly were investigated, a wellness health improvement program was conducted for 12 weeks. Effects before and after the program were examined. The following conclusions were drawn. 1. For the changes of body composition by age associated with sex, while elderly men had a significant difference in BMI, elderly women had a significant difference in B.M.I and body fat percentage. 2. For the changes of senior fitness by age associated with sex, while elderly men had a significant difference in lower body muscle, upper body muscle, upper body flexibility, and transformed general endurance, elderly women had a significant difference in lower body muscle and upper body muscle. 3. For the changes of life habits and nutrition levels by age associated with sex, while elderly men had a significant difference in diet habits and exercise habits, elderly women had a significant difference in exercise habits, stress relief habits, and total nutrition level. Based on the findings, the elderly's participation in the wellness improvement program can enhance lower body muscle which is a risk factor of daily activities and fall and increase upper body muscle which is good to carry and move everyday objects. In addition, it may play a positive role in improving diet habits and changing stress relief and exercise habits, resulting in better health and quality of life of the elderly.

• Journal of Industrial Convergence
• /
• v.20 no.10
• /
• pp.209-218
• /
• 2022

Individuals often report significant relief from pain and stress even after a single session of massage therapy; however, no previous studies have provided objective evidence supporting the effectiveness of a solitary massage therapy session. In the present study, we aimed to investigate the effectiveness of one-time treatment with a spinal thermal massage device reported to exert the same therapeutic effects as massage therapy in terms of pain reduction and stress relief. A man with chronic low back pain (LBP) underwent two rounds of experiments involving spinal massage treatment and bed rest, respectively. Pain was assessed using a visual analog scale, and heart rate variability (HRV) was measured in real-time to examine autonomic nervous system (ANS) activity. Blood samples were obtained at five points during each round of the experiment to examine changes in cortisol, epinephrine, and norepinephrine. Spinal massage significantly reduced pain and enhanced parasympathetic activity when compared with the bed rest condition. In addition, both epinephrine and norepinephrine levels were lower following spinal massage than following bed rest. These results are consistent with the reported effects of conventional massage therapy and support the effectiveness of one-time treatment using a spinal thermal massage device.

• Journal of Korea Entertainment Industry Association
• /
• v.15 no.5
• /
• pp.175-188
• /
• 2021

The purpose of this study was to grasp the influence of mental health upon the lifelong drinking experience in adolescents of non-capital area and capital area through using the 2019 Youth Health Behavior Survey Data. The research subjects included total 57,303 adolescents who participated in the survey among 60,100 adolescents at totally 800 schools with 400 middle schools and 400 high schools. Out of these, 29,384 middle school students and 27,919 high school students were selected. As a result of the research, the mental health that has significant influence upon the lifelong drinking and smoking experience in case of non-capital area appeared to be significant in the perceived subjective health (p<.01), cognitive stress(p<.001), relief from fatigue(p<.001), sadness & despair experience(p<.001), suicide ideation(p<.001), suicide plan(p<.01), and suicide attempt(p<.001). In case of capital area, the mental health of having a significant impact on the lifelong drinking and smoking experience was indicated to be significant in cognitive stress(p<.01), relief from fatigue(p<.001), sadness & despair experience(p<.001), suicide ideation(p<.001), and suicide attempt(p<.001). Based on this outcome, adolescents' drinking problem has influence upon mental health characteristic. Hence, an effort is needed for developing the intervention & education program aiming at the more effective youth drinking prevention through establishing direction and revaluing education program in consideration of mental health factors by region in adolescents of capital area and non-capital area.

• Journal of Korea Entertainment Industry Association
• /
• v.13 no.6
• /
• pp.155-163
• /
• 2019

The purpose of this study was to compare and analyze life habits and senior fitness according to metabolic syndrome by sex and age in the elderly and prevent metabolic syndrome in the elderly. A questionnaire survey for life habits and senior fitness measurement were conducted with 159 old men and 233 old women(a total of 392) who used welfare facilities for the elderly located in G Metropolitan City. The results were as follows. 1. In the comparison of life habits according to metabolic syndrome by sex and age, while old men showed a significant difference in smoking, drinking and drug intake, and stress relief, old women showed a significant difference in drinking and drug intake and dietary habits. 2. In the comparison of senior fitness according to metabolic syndrome by sex and age, while old men had a significant difference in lower and upper body muscle strength, old women had a significant difference in lower and upper body muscle strength, and general endurance. Based on the findings, the elderly's life habits according to metabolic syndrome had a difference in smoking, drinking and drug, and dietary life and senior fitness had a significant difference in muscle strength, flexibility, and endurance. Thus, the elderly need the methods for exercise habits and stress relief for healthy life. Also, old men should steadily strive to improve flexibility, endurance, agility, and balance and old women should steadily strive to improve agility and balance. When the elderly are careful for decreased fitness with age and strive to maintain healthy life habits, their quality of life will be improved and metabolic syndrome will be prevented.

• Fire Science and Engineering
• /
• v.33 no.6
• /
• pp.132-141
• /
• 2019

This study was conducted to investigate the effects of a forest therapy program on post-traumatic stress disorder (PTSD) and mood states of fire fighters. A total of 293 participants completed two psychological questionnaires before and after the program was conducted: the Post Traumatic Stress Disorder Checklist (PCL) and the Profile of Mood States (POMS). Data were analyzed with paired t-test and ANCOVA using SPSS 24.0. The PTSD results showed a significant decrease from 11.38 ± 12.58 points before the program to 6.91 ± 10.50 points after the program. Results of the POMS questionnaire revealed an increase in positive factors and a decrease in negative factors, with a significant overall decrease in POMS results from 8.58 ± 18.47 points before the program to -0.63 ± 15.83 points after the program. As a result of analyzing the differences in stress reduction effects according to the amount of sleep participants had, PTSD showed improvement at 6-8 hours of sleep. These results are expected to be utilized as a basis for stress management and relief in fire fighters.

• The Journal of the Convergence on Culture Technology
• /
• v.6 no.4
• /
• pp.259-266
• /
• 2020

This study is a descriptive research for understanding the health behaviors, job stress, and musculoskeletal subjective symptoms of university employees, and also for examining the influence factors having effects on the musculoskeletal subjective symptoms. Targeting total 158 university employees, the data was collected from July to August 2020. In the results of this study, the characteristics related to health behaviors showed the percentages like the rate of drinking(68.6%), rate of smokers(9.6%), rate of exercising three times or more a week(15.4%), and the rate of regular eating habit(64.7%). The mean score of job stress was 63.7. The musculoskeletal disease symptom group falling under the occupational musculoskeletal subjective symptom standard of NIOSH was 18.6%, and the musculoskeletal subjective symptom of shoulders showed the highest rate. Also, the 29.5% of research subjects responded that the cause for their musculoskeletal pain was work. As the factors having effects on the musculoskeletal subjective symptoms, the sex, age, career experience, and job stress had significant effects on the subjective symptom of shoulder part(p<.01) while the regular exercise had significant effects on the subjective symptom of waist(p<.05). The educational background and regular meals had significant effects on the subjective symptom of legs and knees(p<.05). Thus, in order to prevent the musculoskeletal diseases of university employees, it would be necessary to develop/apply the programs for the relief of job stress, regular exercise, and regular meals.

• Journal of Naturopathy
• /
• v.11 no.1
• /
• pp.1-8
• /
• 2022

Background: A validation study is needed to make domestic applications of German Kneipp therapy. Purpose: The study aims to test the effect of a Kneipp therapeutic program in a domestic forest environment on the autonomic nervous system. Methods: The program was made considering the 4 key elements ('exercise', 'regulative therapy', 'nutrition', and 'phytotherapy') of the Kneipp therapy. Total 3 sessions (once a week for 5 hours in each session) were performed to 40 domestic adults divided into four groups (10 in each group). HRV was measured on the subjects before and after the intervention, and its 6 characteristic parameters (TP, VLF, LF, HF, LF/HF, CSI: Cumulative Stress Index) were compared for statistical analysis. Results: For 33 subjects excluding 7 who were disturbed by interrupt factors during measurements, significant improvements after the intervention, were observed in TP(8.64%, p < ..001), VLF(6.96%, p < .05), LF(15.86%, p < .001), HF(8.46%, p < .01), LF/HF(5.77%, p < .05) and CSI(-16.06%, p < ..001). Conclusions: The Kneipp therapy performed in the forest environment was shown to activate the autonomic nervous system and in particular the sympathetic and parasympatheric nervous to promote heart activity, and was also shown to most significantly reduce cumulative stress. The present observations would be the first preliminary evidence that the Kneipp therapeutic interventation in a domestic forest environment results in positive responses of the autonomic nervous system including stress relief.

• Proceedings of the Computational Structural Engineering Institute Conference
• /
• 1991.10a
• /
• pp.133-138
• /
• 1991

The aim of the present paper is to develop a computer program predicting ultimate fracture strength of initially cracked structure under monotonically increasing external loads. For this purpose, two kinds of 3-D isoparametric solid elements, one 6-node wedge element and another 8-node brick element are formulated along the small deformation theory. Plasticity in the element is checked using von Mises' yield criterion. Elasto-plastic stiffness matrix of the element is calculated taking account of strain hardening effect. If the principal strain at crack tip which is one nodal point exceeds the critical strain dependin on the material property, crack tip is supposed to be opened and the crack tip node which was previously constrained in the direction perpendicular to the crack line is released. After that, the crack lay be propagated to the adjacent node. Once a crack tip node is fractured, the energy of the newly fractured node should be released which is to be absorbed by the remaining part. The accumulated reaction force which was carried by the newly fractured node so far is then applied in the opposite direction. During the action of crack tip relief force, since unloading may be occured in the plastic element, unloading check should be made. If a plastic element unloads, elastic stress-strain equation is used in the calculation of the stiffness matrix of the element, while for a loading element, elasto-plastic stress-strain equation is continuously used. Verification of the computer program is made comparing with the experimental results for center cracked panel subjected to uniform tensile load. Also some factors affecting ultimate fracture strength of initially cracked plate are investigated. It is concluded that the computer program developed here gives an accurate solution and becomes useful tool for predicting ultimate fracture load of initially cracked structural system under monotonically increasing external loads.