• Journal of the Korean GEO-environmental Society
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• v.14 no.10
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• pp.39-47
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• 2013

Recently, there have been various domestic construction activities related to the reclamation of the dredged soils to expand the land use. However, the reclaimed grounds made of the dredged soils cause various problems due to highly compressible and low shear strength nature. Particularly, this nature induces huge problems in case of the harbor facilities and road construction on the reclaimed sites. Furthermore, in the reclamation activities, the marine dredged soils are often used instead of the well sorted sand, which induces problems of compressibilities. Therefore, in this study, the mechanical characteristics of artificial soil mixture of kaolinite representing the marine dredged soils and the pond ash. A large consolidometer is designed and manufactured to produce the artificial soil mixture. To represent various mixing ratio between the fly ash and bottom ash in the pond ash, six samples with the same stress history are made with different mixing ratio among kaolinite, bottom ash and fly ash. Isotropically consolidated and undrained compression tests are performed to investigate the shear characteristics of soil mixtures. Based on the experimental results, as the components of mixed ash increase, the friction angle increase and the cohesion values decrease. Also, the porepressure parameters at failure, Af increase with the mixing components of the pond ash. The portion of bottom ash has more impact on the shear behavior than that of fly ash.

• Journal of Elementary Mathematics Education in Korea
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• v.17 no.3
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• pp.523-539
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• 2013

The object of this study is to compare and analyze mathematically gifted and non-gifted elementary students in the family system and career attitude maturity, understand the characteristics of the former, and provide assistance for career education for both groups. The subjects include 145 mathematically gifted elementary students (73 fifth graders, 72 sixth graders) and 167 non-gifted students (78 fifth graders, 89 sixth graders) in G educational agencies. Materials for the experiment include amended family system test and career attitude maturity test. While t-test was conducted to solve the first research question, Pearson's correlation analysis was performed to solve the other one. The research findings were as follows: First, mathematically gifted elementary students, compared to non-gifted students, turned out to have higher rates of the family system and career attitude maturity rate and showed statistically meaningful positive relationship. Second, the lower components of the family system and career attitude maturity, there seems to be no relationship between family-flexibility and finality. However, among other components, there was a level of significance at 5% which shows statistically meaningful positive relationship. In summary, this found that the family system is able to have an effect on the career attitude maturity for both mathematically gifted elementary students and non-gifted students. Hence, it need to be considered the components of family system when the teacher guides mathematically gifted elementary students and non-gifted students associated with their career.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.29 no.2
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• pp.83-91
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• 2017

In order to cope with the abnormally high waves during the storm surge due to climate change, various methods have been proposed for interlocking adjacent caissons to enhance stability of harbor structures. Among the methods, it was studied the method based on an open-cell caisson having reduction effect increasing the cohesion with adjunction caissons by filling materials such as crushed rocks in an inter-cell formed by two facing open-cells which consist of transverse walls. It is necessary to investigate the shear behaviors of an inter-cell to secure the stability using calculating shear forces on inter-cell under oblique wave loadings. It was analyzed the shear force share ratio with the length of internal and external wall and the number of internal walls. Numerical results show that 60~70% of the shear load is transmitted to adjacent caisson through the internal walls, more than 30% is through the external wall. It was applicable in the assumption that filling materials was uniformly distributed in inter-cells, and further studies were worth consideration on other conditions under construction.

• Journal of Animal Science and Technology
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• v.46 no.5
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• pp.763-772
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• 2004

The patterns of fungal growth and fiber digestion under the microscope, and tile productions of fibrolytic enzyme were studied in an in vitro culture with Neocallimastix frontalis SA when either filter paper or rice straw was provided as sole energy source. Under the microscopic observation, active zoospores attachment, sporangium development and complex rhizoidal system were founded on the surface and at the edge of filter paper. After 7 days of incubation, a reduced fiber mass, a decreased fiber cohesion and a weakened fiber structure by fungal digestion were clearly observed. Similar fungal development was observed with rice straw, but fungal growth and digestion took place mostly on the damaged and exposed portion of rice straw. Although there were some differences in absolute concentration and pattern, the concentration of both cellulase and xylanase increased with incubation time with the higher activity being obtained with filter paper. Their differences were large especially after 48 and 96hr of incubation(P< 0.05). The filter paper was more good inducer of cellulolytic and xylanolytic enzymes compared with complex substrate, rice straw. These findings suggest that the filter paper is the better energy source for N frontalis than the complex substrate, and structural disintegration by physical process is able to help rumen fungal growth on the lignified roughage although anaerobic rumen fungi have mechanical and enzymatic functions for fiber digestion.

• Tunnel and Underground Space
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• v.15 no.3 s.56
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• pp.223-227
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• 2005

The physical and mechanical properties of volcanic glass, which is distributed in the Samho area, South Korea were studied. Laboratory rock tests were carried out in order to obtain the various properties of rocks. Specific gravity, water content, absorption, porosity and wave velocity were measured for the physical properties. Uniaxial and triaxial compressive tests, Brazilian test and point load test were also performed for the mechanical properties. The tests of volcanic glass revealed that the apparent specific gravity, water content and absorption were 2.28, $1.67\%$ and $1.72\%$, respectively. Porosity $(3.87\%)$ was lower, whereas P-wave velocity (5330m/s) and S-wave velocity (2980 m/s) were relatively higher. Brazilian tensile strength ot 7.2MPa, and point load strength of 2.6MPa were among the mechanical properties of the rock. Uniaxial compressive strength (62.4MPa) estimated ken point load strength was very closed to the value (66.0MPa) from the uniaxial compressive test. Young's modulus and Poisson's ratio were E=43.2 GPa and v=0.28, respectively. Drawing the tangent line to Mohr-Coulomb failure criterion showed the cohesion of 20.1MPa and internal fraction angle of $28.6^{\circ}$.

• Journal of the Korean Geotechnical Society
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• v.29 no.12
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• pp.35-44
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• 2013

In this study, a particle method without using grid was applied for analysing large deformation problems in soil flows instead of using ordinary finite element or finite difference methods. In the particle method, a continuum equation was discretized by various particle interaction models corresponding to differential operators such as gradient, divergence, and Laplacian. Soil behavior changes from solid to liquid state with increasing water content or external load. The Mohr-Coulomb failure criterion was incorporated into the particle method to analyze such three-dimensional soil behavior. The yielding and hardening behavior of soil before failure was analyzed by treating soil as a viscous liquid. First of all, a sand column test without confining pressure and strength was carried out and then a self-standing clay column test with cohesion was carried out. Large deformation from such column tests due to soil yielding or failure was used for verifying the developed particle method. The developed particle method was able to simulate the three-dimensional plastic deformation of soils due to yielding before failure and calculate the variation of normal and shear stresses both in sand and clay columns.

• Korean Journal of Family Social Work
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• no.61
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• pp.93-136
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• 2018

The purpose of this study is to find specific practice methods of single parents self-help groups in community welfare centers. A participatory action research was conducted to achieve the purpose. Six social workers and three researchers participated in the study who shared the problem of lack of specific practice methods even though a self-help group was useful for self-reliance and empowerment of low-income single-parents. Various activities such as reading articles, analysis of each self-help group, case studies, and learning facilitation methods were conducted during 10 meetings. At the same time, peer supervision proceeded at each meeting. The progress of each group was shared, the application of practice methods and plans were discussed, and applying discussed methods to group practice and reviewing the process and outcomes of the practice were repeated in the peer supervison. As a result, the following positive changes appeared: First, the goals and vision of each group became clearer. Second, initiative of the members was promoted. Third, intimacy, mutual cooperation, the attatchment to the group were strengthened. A qualitative analysis was also conducted on the content discussed. As a result, 17 practice methods were derived in four themes such as initiative/ empowerment, cohesion, leadership, and destandardization. Practice issues concerning single parents self-help groups in community welfare centers were discussed based on the results.

• Korean Journal of Social Welfare Studies
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• no.37
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• pp.429-455
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• 2008

The purpose of this study is to generate a substantive theory that accounts for the social readaptation of the women who have engaged in prostitution and propose a practical program for them. We used the grounded theory developed by Strauss and Corbin(1990). Raw data were collected through the in-depth interview, documents and observation. We used constant comparative method for the data analysis. The nine women who had the exprience of prostitution have participated in this study. As a result of the data analysis, in open coding were generated 116 concepts, 29 subcategories and 12 categories, In axial coding the outcomes of a paradigm model were as follows. The causal conditions were named 'hostile environment' and 'the self endowed stigma'. The phenomenon turned out to be 'living as an anonymous being'. The contextual conditions were named 'cohesion of family', 'being pushed' and 'shrinked emotion'. The intervening conditions were presented to be 'desire of self restoration as a social being', 'reactionary reconstruction'. The action/interaction strategies turned out to be 'shifting of social status', 'neighbor alliance'. The consequences were presented to be 'psychological wayfarer' and 'tentacular living'. In selective coding we found a core category, 'repetition of leaving and returning from the life world'. Based on the phenomenon, two types of participants life attitudes were found as follows : present hesitating type, self concealing type. Following the adove results, We finally suggested the need to develope a community oriented case management model.

• Journal of the Korean Society of Child Welfare
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• no.40
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• pp.139-166
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• 2012

The purpose of this study is to investigate the effects of poverty on the psychosocial adjustment of adolescents. Particularly, this study seeks to examine the mediating effects of neighborhood environments and parental depression. The 2008 'the Korean Youth General Survey' data were utilized. We analyzed data from 2,218 adolescents between the ages of 12 and 18 and their parents. We defined poverty as the income-to-needs ratio, and measured neighborhood environment using the degrees of neighborhoods' disorder, attachment, cohesion, and informal social control. Adolescents' externalizing and internalizing problem behaviors were used as indicators of adolescents' psycho-social adjustment. Structural equation modeling was utilized as the major analytic method. This study found that adolescents in low income families were more likely to reside in disadvantaged and dangerous neighborhoods. More importantly, the results revealed that psychosocial adjustment of the adolescents was indirectly influenced by poverty through the mediators, neighborhood environment and parental depression. Based on the results, we discussed policy and practice implications, including various interventions that may improve parental mental health and neighborhood environment of low income communities.

• Korean Journal of Social Welfare Studies
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• v.48 no.2
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• pp.331-357
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• 2017

In this study, we explored the degree to which foreign workers in Korea are satisfied with their lives. We examined the extent of the respondents'educational mismatch, their experiences of discrimination, and the empowerment influence on their degree of life satisfaction. Based on this, we developed practical implications to improve foreign workers'life satisfaction in the country. The results show that life satisfaction significantly rises as the respondents'educational credentials increasingly match with the criteria for their respective jobs, given that they have not experienced discrimination and their empowerment level is high. Based on these outcomes, we proposed the following important policy measures: mediation and diminishing educational mismatch during job searches, establishing legal and institutional frameworks to prevent discrimination, and placing greater emphasis on efforts to improve foreign workers'empowerment. We expect our findings to provide an important empirical basis for efforts to facilitate foreign workers'integration into Korean society. This study is the first attempt to apply concepts such as foreign workers'empowerment and educational mismatch -as defined by the Organisation for Economic Cooperation and Development's Programme for the International Assessment of Adult Competencies (OECD PIAAC) -to foreign workers in Korea.