• Korean Journal of Health Education and Promotion
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• v.28 no.1
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• pp.103-113
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• 2011

Objective: This study was conducted to investigate the relationship between the degree of stress and social support among residents in a rural area. Methods: We used the baseline data of the Korean Genomic Rural Cohort (KGRC), a sub-cohort of the Korean Genome Epidemiology Study (KOGES) that collected data about relationships among environmental, genetic risk factors, and chronic illness in Korean adults since November 2005. The cases chosen for the study included 1737 men and women, aged 40 to 70, living in a rural area of Wonju-city, South Korea. A questionnaire interviewing method was addressed in 2006. The final participants consisted of 1349 participants, of which 589 were male (43.7%) and 760 were female (56.3%). We applied the hierarchical multiple regression analysis with three stages. The first and second stages include socio-demographic and health-related behaviour factors and the third stage includes more social support factors. Results: The main findings revealed that the amount of social support and health-related behaviour significantly influenced the level of stress the subjects reported. The degree of stress was shown to be significantly higher for the following individuals: females, those who were divorced, the bereaved, participants who suffer from chronic disease, and non-exercisers. Low social support was shown to be negatively associated with stress. Conclusion: Social support factors along with socio-demographic and health-related behavior had an influence on stress levels in Korean rural adults. It is necessary to relieve residents from stress through diverse social support programs and healthy living initiatives.

• KSBB Journal
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• v.20 no.4
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• pp.305-310
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• 2005

Reconstruction of rabbit corneal epithelium was performed through dynamic culture method using self-manufactured amniotic membrane supporter and lyophilized amniotic membrane. Rabbit corneal epithelial cells were cultured and cryopreserved after isolation from limbus, and the cells could be proliferated by passage number 10. The basal layer was well formed, and the epithelium layer was constructed tightly by the increase of cell proliferation and differentiation by dynamic culture method than static culture. Thus, the reconstruction of the corneal epithelium using lyophilized amniotic membrane is considered to be a good in vitro model for transplantation of corneal epithelium to patients with a severely damaged cornea.

• Journal of the Korea Concrete Institute
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• v.15 no.6
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• pp.848-855
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• 2003

During concrete placement, the partially distributed load due to the concrete placement paths creates the lateral force in the connection parts of the shore. In order to restrain this lateral force, the nails must be used in the upper and lower connection parts of shores. But, for the convenience of the construction and dismantling of the shores, the workers hardly use the nails. In this case, the connections of shore cannot resist the shear force and rotation. And this situation may cause the collapse of form-shore system. Therefore, contact and spring models for the connection analysis of the form-shore systems are required. If we take into account this construction situation, we need to understand the effects of shear and rotation stiffness according to the several types of connection parts in shores as a case study. This study evaluates the shear and rotation stiffness of the connection parts of shores according to the variations of the lengths, numbers and positions of nails, and then presents the experimental results depending on the end conditions of shores. And, these results can be used as a spring model and critical load evaluation data for the connection analysis of form-shore system.

• Journal of the Korea Concrete Institute
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• v.28 no.3
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• pp.257-265
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• 2016

The failure behavior of reinforced concrete beams is governed by the mechanical relationships between the shear span-to-effective depth ratio, flexural reinforcement ratio, load and support conditions, and material properties. In this study, two simple indeterminate strut-tie models which can reflect all characteristics of the failure behavior of reinforced concrete beams were proposed. The proposed models are effective for the beams with shear span-to-effective depth ratio of less than 3. For each model, a load distribution ratio, defined as the fraction of load transferred by a truss mechanism, is also proposed to help structural designers perform the rational design of the beams by using the strut-tie model approaches of current design codes. In the determination of the load distribution ratios, the effect of the primary design variables including shear span-to-effective depth ratio, flexural reinforcement ratio, and compressive strength of concrete was reflected through numerous material nonlinear analysis of the proposed indeterminate strut-tie models. In the companion paper, the validity of the proposed models and load distribution ratios was examined by applying them to the evaluation of the failure strength of 335 reinforced concrete beams tested to failure by others.

• Journal of the Korea Concrete Institute
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• v.28 no.4
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• pp.489-496
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• 2016

Recently, a concern about hollow core precast concrete (PC) slab has been increased as a method to improve the construction ability by reducing the self weight of structures during the construction. Hollow core slab which is known as a typical PC slab in domestic construction of PC building has a problem to put shear reinforcements in the web of element during the production of element in the factory. With regard to this point, recently, tripple ribs slab (TRS) which can be said as a new type of half PC slab system was developed. In TRS, it is possible to place shear reinforcements in PC element during the production of the element in the factory. This paper presents the shear test result of TRS which was done by one point loading test under simple support condition. Test parameters are the presence of cast-in-place (CIP) concrete and the contribution of lattice bars. From the test, it was found that the TRS has sufficient shear capacity to resist the design load and its strength can be predicted by the code equations for general beam. It is recommended to ignore the strength of lattice bar in the calculation of shear strength during the construction since its contribution is too low to be considered when CIP is not casted.

• The Korean Journal of Financial Management
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• v.24 no.2
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• pp.81-111
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• 2007

The agency relationship between managers and shareholders has the potential to influence decision-making in the firm which in turn potentially impacts on firm characteristics such as value and leverage. Using an agency framework, we examine the relation between ownership structure and capital structure during post-IMF period. We used the balanced panel data for 378 korean listed companies during the 1999-2005. The panel data sets consist of time-series observation on each of 378 cross-sectional units. The results indicate a non-linear U-shaped relation between the level of managerial share ownership and leverage with the relation reaching a minimum at 58.48 per cent of management share ownership. As managerial share ownership increase from a low level, managers have incentive to reduce the debt level for decreasing the financial risk, resulting in a lower lever of debt. However, when corporate managers hold a significant proportion of a firm's shares, managers have incentive to increase the debt level for leverage effects, resulting in a higher lever of debt.

• Journal of the Korean Electrochemical Society
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• v.19 no.1
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• pp.21-27
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• 2016

Vanadium redox flow batteries (VRFBs) using the electrolytes containing various vanadium ions in sulfuric acid as supporting solution are one of the energy storage devices in alternatively charging and discharging operation modes. The positive electrolyte contains $V^{5+}/V^{4+}$ and the negative electrolyte $V^{2+}/V^{3+}$ depending on the operation mode. To prevent the mixing of two solutions, proton exchange membranes are mainly used in VRFBs. Nafion 117 could be the most promising candidate due to the strong oxidative property of $V^{5+}$ ion, but causes high crossover of electroactive species to result in a decrease in coulombic efficiency. In this study, the composite membranes using Nafion ionomer and porous polyethylene substrate were prepared to keep good chemical stability and to decrease the cost of membranes, and were compared to the properties and performance of the commercially available electrolyte membrane, Nafion 117. As a result, the water uptake and ionic conductivity of the composite membranes increased as the thickness of the composite membranes increased, but those of Nafion 117 slightly decreased. The permeability of vanadium ions for the composite membranes significantly decreased compared to that for Nafion 117. In a single cell test for the composite membranes, the voltage efficiency decreased and the coulombic efficiency increased, finally resulting in the similar energy efficiency. In conclusion, the less cost of the composite membranes by decreasing 6.4 wt.% of the amount of perfluorinated sulfonic acid polymer due to the introduction of porous substrate and lower vanadium ion permeability to decrease self-discharge were achieved than Nafion 117.

• Korean Journal of Social Welfare
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• v.36
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• pp.285-307
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• 1998

This study explored three issues in regard to the relationship among stressful life events, coping, successful outcomes, life satisfaction and depression. The first issue was about the differences in the level of use among eight coping strategies according to the type of stressful life events. The second issue dealt with the differences between those who achieved successful outcomes and those who did not in the use of coping strategies. The third issue was if the different use of coping strategies was related to the level of life satisfaction and depression. Stressful life events were divided into problems of four areas such as health, finance, family relations including well-being of family members, and work Coping was assessed by eight factors. The survey data collected from 221 community residing adults was used for analyses. Findings suggested that the level of the use of escape-avoidance was very low while the level of the use of planful problem solving, seeking positive meaning, self control, and accepting responsibility was high for all stressful life events. It was also found that in some stressful life events those who achieved successful outcomes used more planful problem solving, more seeking positive meaning and less escape-avoidance than those who did not achieve successful outcomes. Finally, for almost all of the stressful life events, the use of more planful problem solving was related to either higher level of life-satisfaction or lower level of depression while the use of more escape-avoidance was related to lower level of life-satisfaction and higher level of depression. According to the results, implication for social work intervention was discussed.

• Korean Journal of Social Welfare
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• v.57 no.1
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• pp.31-60
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• 2005

This study was performed to analyze empowerment process of the disabled. Participants were 11 disabled college students and they were individually face-to-face in-depth interviewed until data were saturated. This study used the grounded theory approach based on Strauss and Corbin(1998). With the qualitative constant comparative analysis, 105 concepts, 22 subcategories, and 12 categories were generated. In the axial coding, a paradigm model was proposed as follows: The central phenomenon of the empowerment process of the disabled adolescents was 'Rising from the Limits'. The causal conditions were 'Just living' and 'realizing disabilities'. The contextual conditions were 'Being excluded', 'But wishing', and 'Breaking down'. The intervening conditions were 'Without giving up' and 'Taking support'. The action/interaction strategies were 'Grasping own lifestyle' and 'Being proactive'. The consequences were 'Acquiring the self-control', 'Getting generosity', and 'Participating in society'. In the selective coding, the core category was 'to live together stately with grasping own lifestyle pro-actively as the disabled'. Based on the core category, three types and 4 stages of the empowerment process of the disabled adolescents were found. The types were 'Social change oriented type', 'Self-development oriented type', and 'Passive effort oriented type' and the stages took 'Isolation stage', 'Rising stage', 'Mastering stage' and 'Stately being together stage'. In particular, this process had the circulation structure of which these 4 stages are not terminated, and developed and repeated. In conclusion, these results convey to us the understanding and knowledge about empowerment process of the disabled as their healthy -whole and unique- development process. And some implications and suggestions for the social work services and theories about the disabled focusing on the pre-adulthood period.

• Korean Journal of Social Welfare
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• v.54
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• pp.221-243
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• 2003

Activity theory explains that the old people participate in social activity as a role-substitute from loss of roles given by work and family. It is possible to enhance their life satisfaction through these activities. Based on this activity theory, this study aims at explore the role substitute of voluntary activities and to analysis whether volunteering commitment has an effect on life satisfaction. Data were collected by using survey questionnaires to the elderly over 55 years old who participated in voluntary activity at 25 Volunteer Centers in Seoul. The Activity theory was operationalized by job or joblessness, family type, achievement type obtained through voluntary activity The results are as follows. (1) Job or joblessness has effect on the activity frequence and activity time. (2) Social achievement after voluntary activity has effect on the duration only (3) And the family type did not have any effect. These three variables of activity theory do not have an effect on life satisfaction. The elderly volunteering commitment was explained by variables other than activity theory such as reward, health, education, sex. And the elderly volunteer's life satisfaction were affected by the family types and their economic status. These results imply that the Korean elderly voluntary activities could be expained partially by Activity theory. Also for these elder volunteers's life satisfaction, qualitative respects such as achievements through voluntary activity, and concerns and support by agencies are more important than the time they imput in voluntary activities.