• Computers and Concrete
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• v.31 no.3
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• pp.267-276
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• 2023

The main purpose of the current research is to develop an efficient two variables trigonometric shear deformation beam theory to investigate the buckling behavior of symmetric and non-symmetric functionally graded carbon nanotubes reinforced composite (FG-CNTRC) beam resting on an elastic foundation with various boundary conditions. The proposed theory obviates the use to shear correction factors as it satisfies the parabolic variation of through-thickness shear stress distribution. The composite beam is made of a polymeric matrix reinforced by aligned and distributed single-walled carbon nanotubes (SWCNTs) with different patterns of reinforcement. The material properties of the FG-CNTRC beam are estimated by using the rule of mixture. The governing equilibrium equations are solved by using new analytical solutions based on the Galerkin method. The robustness and accuracy of the proposed analytical model are demonstrated by comparing its results with those available by other researchers in the existing literature. Moreover, a comprehensive parametric study is presented and discussed in detail to show the effects of CNTs volume fraction, distribution patterns of CNTs, boundary conditions, length-to-thickness ratio, and spring constant factors on the buckling response of FG-CNTRC beam. Some new referential results are reported for the first time, which will serve as a benchmark for future research.

• Journal of Korean Society of Forest Science
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• v.112 no.1
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• pp.105-116
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• 2023

As forest fires' scale has increased, they have become disasters that destroy not only forests but also property, human psychological balance, and even human lives. As a result, governmental support has become a crucial part of the forest fire restoration process. Quickly restoring victims' quality of life (QOL) from not only an ecological perspective but also from their human perspective has become an important goal. Therefore, through structural equation modeling, this study analyzed effects of government support, post-traumatic stress disorder (PTSD), and resilience on 195 Uljin and Samcheok forest fire victims' QOL. In the final research model, the total standardized effect on QOL of government support to PTSD and resilience was found to have significant effect (0.417). By path, the effect of government support on QOL through resilience was verified as 0.172. Examination of the path between latent variables revealed that resilience had the greatest influence on QOL, and government support had a significant effect, thus confirming that they were the main factors affecting QOL.

• Journal of the Korean Geotechnical Society
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• v.23 no.6
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• pp.97-102
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• 2007

Though the stability analysis of soil slopes widely employs the limit equilibrium method, the study on the jointed rock slopes must consider the direction of joint and the characteristics of Joint at the same time. This study analyzes the result of the change in the factors which show the characteristics of discontinuity and the shape factor of rock slopes, and so on, in an attempt to validate the propriety as to the interpretation of jointed rock slope stability which uses the general finite element program. First, the difference depending on the flow rules was compared, and the factor effect study was conducted. The selected independent variables included the direction of joint which displays the mechanical characteristics of discontinuity, adhesive cohesion, friction angle, the inclination and height of rock slope which reveal the shape of slope and surcharge load. And the horizontal displacement was numerically interpreted at the 1/3 point below the slope, a dependent variable, to compare the relative degree of factor effects. The findings of study on factor effects led to the validation that the result of horizontal displacement for each factor satisfied various engineering characteristics, making it possible to be applied to stability interpretation of jointed rock slope. A modelling is possible, which considers the application of the result of real geotechnical surveys & laboratory studies and the non-linear characteristics when designing the rock slope. In addition, the stress change which may result from the natural disaster, such as precipitation, and the construction, can be expressed. Furthermore, as the complicated rock condition and the ground supporting effect can be considered through FEM, it is considered to be very useful in making an engineering decision on the cut-slope, reinforcement and so on.

• Journal of the Korean Geotechnical Society
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• v.25 no.6
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• pp.5-16
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• 2009

The is study is to evaluate the small strain shear modulus ($G_{max}$) of Busan clay using in-situ penetration tests. A series of dilatometer tests (DMT) and piezocone penetration tests (CPTu) are performed at Busan newport and Noksan sites, and hybrid oedometer tests are also carried out on the specimens obtained from both sites. The $G_{max}$ is evaluated from the shear wave velocity ($V_s$) measured by the bender elements installed at the boundary of oedometer cell. By analyzing these data, the relationship of $G_{max}$ and state variables, such as confined stress and void ratio, is developed. The analysis of lab and in-situ test results reveals that the ratio of $G_{max}$ to $q_t$ is inversely proportional to the plasticity index while the ratio of $G_{max}$ to $E_D$ has a linear relationship with ($I/I_D$)$(p_a/{\sigma}'_v)^{0.5}$. Two correlations suggested in this study, based on CPT and DMT results, appear to provide reasonable predictions of the small strain shear modulus.

• Asia-pacific Journal of Multimedia Services Convergent with Art, Humanities, and Sociology
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• v.7 no.2
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• pp.701-710
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• 2017

This study investigated the effect of cash benefit and in-kind benefit policy supported by disabled children on the satisfaction of service care of main caregiver. The results of this study are as follows. First, the parental stress, parenting burden, and family members' difficulties were investigated. However, the research on the salary policy supported by the handicapped children has been scarce, and it has been found that the research on the service satisfaction of the main caregiver is also insufficient by the type of salary. The purpose of this study is to examine the effect of variables (parents gender, child gender, parents age, child age, disability grade, average income) on service satisfaction. As a result, parents age, child age, and child gender showed statistically significant effects on service satisfaction. This resulted in statistically significant overall effects on the application process, economic burden, support and selection criteria, service volume, and overall satisfaction. Based on the results of the study, the implications for cash benefits and in-kind benefits could be improved by increasing the amount and scope of benefits, and customized services considering the age of the handicapped children, ultimately improving the service satisfaction of the main caregiver.

• 한국노년학
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• v.29 no.4
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• pp.1591-1609
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• 2009

Adult child caregivers and spousal caregivers might deal with differential challenges. Studies about caregivers' psychological outcomes, however, tended to investigate associations between caregiving and its outcomes by pooling adult child caregivers and spousal caregivers together. By using a U. S. sample of family caregivers who assisted a relative with dementia, this study examined whether the relationship of caregivers to care receivers (daughter caregivers or spousal caregivers) made a difference in levels of depressive symptoms. The result showed that wife caregivers were more likely to be depressed than daughter caregivers. For daughter caregivers, role overload, role captivity, and behavior problems significantly influenced on depression. Besides these variables, the level of education was a significant predictor for wife caregivers. Role captivity and behavior problems significantly impacted on depression for husband caregivers. Thus, role captivity and behavioral problems were common predictors for all the caregivers. Specifically, higher levels of role captivity and behavioral problems were likely to make caregivers more depressed. The implication of these results were discussed.

• Korean Journal of School Psychology
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• v.9 no.2
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• pp.289-309
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• 2012

This is a longitudinal study which analyzed suppression effects of active/passive coping strategies on academic burnout, using a structural equation modeling. A total of 357 middle school students participated in this study for two waves. In order to measure the levels of students' coping strategies and academic burnout, the Ways of Coping Checklist and the Korean version of Maslach Burnout InventoryStudent Survey(MBI-SS) were used. Latent variables were constructed with standardized residuals computed from a simple linear regression in order to capture the intra-individual changes between two time points. The results of this study are like below. First, the relationship between the change of active coping strategy and the change of passive coping strategy is positively and significantly related with each other. This result indicates that students under stress use various coping strategies simultaneously. Second, significant suppression effects were revealed between the change of active coping strategy and the change of passive coping strategy. That is, when controlling passive coping strategy, the negative relationship between the change of active coping strategy and the change of academic burnout increased. On the other hand, when controlling active coping strategy, the positive relationship between the change of passive coping strategy and the change of academic burnout increased. Based on these results, the value of this study and implications for counseling were discussed.

• Korean Journal of Culture and Social Issue
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• v.19 no.3
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• pp.319-341
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• 2013

This study investigated the mediating effects of social support and coping on the relation between traumatic event type, posttraumatic growth and wisdom by the data from 247 adults by using path analysis. Besides, the difference of the level of posttraumatic growth and related variables between traumatic event type groups. At first, The results of the MANCOVA, person-related traumatic event group were higher than the non-personal traumatic event group in negative coping and trauma stress level, and lower in social support, positive coping, posttraumatic growth and wisdom. The path analysis results shows that traumatic event type was related to wisdom by mediate factors. Traumatic event type affected wisdom through social support, positive coping, posttraumatic growth. The significant mediators were social support, positive coping, posttraumatic growth. Negative coping was not a significant mediator between event type and posttraumatic growth. The results show that non-personal traumatic event group are tends to have high level of social support, positive coping, posttraumatic growth, and wisdom. In the end, we described that the implication and the limitation of this study and suggestions for following studies.

• Journal of the Korean Society of Marine Environment & Safety
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• v.29 no.7
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• pp.992-1001
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• 2023

OWEC (Overtopping Wave Energy Converter) is a wave power generation system using the wave overtopping. The performance and safety of the OWEC are affected by wave characteristics, such as wave height, period. To mitigate this issue, optimal OWEC designs based on wave characteristics must be investigated. In this study, the environmental conditions along the Ulleungdo coast were used. The hydraulic efficiency of the OWEC was calculated using SPH (Smoothed Particle Hydrodynamics) by comparing 4 models that changed the substructure. As a result, it was possible to change the substructure. Through design optimization, a new truss-type structure, which is a substructure capable of carrying the design load, was proposed. Through a case study using member diameter and thickness as design variables, structural safety was secured under allowable stress conditions. Considering wave load, the natural frequency of the proposed structure was compared with the wave period of the relevant sea area. Harmonic response analysis was performed using wave with a 1-year return period as the load. The proposed substructure had a reduced response magnitude at the same exciting force, and achieved weight reduction of more than 32%.

• Journal of The Korean Society of Integrative Medicine
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• v.12 no.2
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• pp.121-131
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• 2024

Purpose : This study aimed to investigate the leisure satisfaction of participants in the Geod-Jyu walking program and to examine the relationship between health promotion behaviors and quality of life. In addition, we investigated the impact of leisure satisfaction with walking among program participants on health promotion behaviors and quality of life. By clarifying these relationships, we aimed to identify factors of leisure satisfaction with walking that could enhance participants' health promotion behaviors and quality of life. Methods : A survey was conducted among 301 participants enrolled in the Geod-Jyu walking program in Chungcheongnam-do, with 288 responses analyzed. Data analysis included Pearson's correlation, confirmatory factor analysis, and multiple regression analysis using SPSS 27.0. Result : Leisure satisfaction exhibited a positive correlation with health promotion behavior (r=.544, p<.01) and quality of life (r=.478, p<.01). Furthermore, health promotion behavior showed a positive correlation with quality of life (r=.636, p<.01). Leisure satisfaction positively influenced quality of life, with physiological satisfaction (β=.16, t=2.32) and relaxation satisfaction (β=.15, t=2.04) emerging as notable contributors. In addition, leisure satisfaction had a significant positive impact on health promotion behaviors, with psychological satisfaction (β=.24, t=3.09) and educational satisfaction (β=.20, t=3.09) playing key roles. Health promotion behavior had a positive impact on quality of life, with all sub variables exhibiting significant positive effects in the following order: self-actualization (β=.24, t=4.16), stress management (β=.22, t=3.97), exercise (β=.22, t=4.05), and health responsibility (β=.12, t=2.14). Conclusion : The findings indicate that factors related to physical and rest satisfaction, as well as health-promoting behaviors facilitated by walking, significantly affected the quality of life among Geod-Jyu participants. Thus, promoting leisure satisfaction and engaging in health-promoting activities through walking can enhance overall well-being. Encouraging participation in the Geod-Jyu walking program is critical for physical and psychological benefits, and for promoting healthier behaviors. Further development of Geod-Jyu is expected to enhance walking satisfaction, promote self-care skills for health management, and positively influence quality of life.