• Journal of the Korean GEO-environmental Society
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• v.5 no.4
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• pp.25-31
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• 2004

In conventional activated sludge process, COD fractions in wastewater are important parameters, significantly. Depending on characteristics of influent COD fractionation, activated sludge process requires a major change of a process operation to ensure meeting a stricter standards. In order to validate and evaluate the accuracy of the traditional COD fractionation methodologies, readily and slowly biodegradable COD was mixed using glucose and peptone as a sole carbon source in a synthetic wastewater, respectively. In this research, prediction of the COD fraction was made using the OUR(Oxygen Utilization Rate) and the NUR(Nitrate Utilization Rate) experiments. The result showed that COD fractions calculated by OUR experiment were similar to the composition of synthetic wastewater. On the other hand, it was found that an error was generated during the NUR experiment. This error was due to the intracellular storage period for storage microorganisms such as PAOs, and the error in COD fraction was observed about 8-14 % in terms of Total COD.

• Journal of the Korean GEO-environmental Society
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• v.14 no.11
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• pp.33-46
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• 2013

Recently, the projects which are to increase the capacity of the flood control are being actively performed because of the abnormal climate changes throughout the country. In this study, the regression analysis was performed using both Kelvin model and the real settlement measured at the crest of the existing concrete face rockfill dam(CFRD) to estimate the long-term deformation behavior characteristics such as creep which occurs without additional load. In addition, the effects on changes in physical properties (E, G, K) of the dam construction materials by deformation characteristics of the dam were evaluated, and the reasonable stability analysis method of the dam was proposed to obtain the long-term stability considering the changes in physical properties induced by the long-term deformation behavior in case of heightening the existing dams.

• Journal of the Korean GEO-environmental Society
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• v.10 no.7
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• pp.33-41
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• 2009

In the case of underground power utilities pipe such as circular pipe, the most difficult problem is low compaction efficiency of the bottom of pipe inducing the failure of utilities. To overcome this problem, various studies have been performed and one of these is CLSM (controlled low strength materials) accelerated flow ability. CLSM has already been stage of commercial use in the foreign countries led by power company. In this study, we estimated the behavior of flexible pipe with flowable backfill materials and sand to compare on the DB24 load. The results showed that the deformation of flexible pipe is affected by types of backfill materials. CLSM shows better behavior characteristics than compacting sand. But numerical and analytical results that peformed to compare to the field test results showed big gap with the field results.

• Journal of the Korean GEO-environmental Society
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• v.10 no.6
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• pp.69-77
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• 2009

The shortage of bearing capacity and settlement, shear deformation may occur when constructing a structure such as harbor, airport and bridge on soft ground such as marine clay, silty clay, sandy soil because it is very soft. The various ground improvement methods were applied to obtain preceding settlement of soft ground and strength increase. The vertical drain method has been used to reduce the required time for consolidation of the soft ground. Especially, the PBD (Plastic Board Drain) has been widely used among in the vertical drain method. In this study, a behavior of characteristic was evaluated by operating a compound drainage capacity test about the PBD (Plastic Board Drain) method applied in soft clay in deep depth. As a result, the settlement gradually occurred with increase of surface load. The consolidation settlement was processed with dissipation of pore pressure after surface load of $500kN/m^2$. Accordingly, it was found that change of settlement through load steps was resulted from dissipation of pore pressure. It was also found that the drainage capacity of vertical drains was considerably reduced with pressure increase and time elapse.

• Journal of the Korea institute for structural maintenance and inspection
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• v.9 no.1
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• pp.251-258
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• 2005

Up until now, most protection design has been concerned primarily with concrete's exterior protection from corrosion, its waterproof ability and its reparability. However, there are many cases in which service life of the concrete is shortened because suitability of the type of concrete surface has not been thoroughly investigated in the development process. According1y, this paper presents the development and test of the material for its reparability and its protection against corrosion in the case of wet surfaces (i.e. water supply facilities, sewage systems, and port facilities) in this country. From the test, both A type and B type are excellent for durability in watertightness, chemical resistance and abrasion. Test results of adhesive strength over $15kgf/cm^2$ under both wet and dry conditions, curing conditions and various temperatures conditions were also achieved in field tests.

• Journal of the Korean GEO-environmental Society
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• v.6 no.2
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• pp.21-30
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• 2005

The purpose of this study was to evaluate the effect of vegetation on the cutting slope applied by vegetation system in the whole land. The engineering characteristics of slopes were investigated using the face mapping and physical tests. From the statistical methods, a relationship between a geologic stratum and degree of covering was independent. Therefore, the afforestation of slope was affected more by condition of vegetation as direction and opening of joints, and a topsoil state than by conventional classification of layer. It was concluded that the adjustable vegetation on the slope considering condition of geometric shape of slope, joint data and spontaneous type could make useful early afforestation.

• Journal of the Korean GEO-environmental Society
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• v.20 no.10
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• pp.39-46
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• 2019

The interaction between the ground and structures should be considered for seismic design of group piles supporting the superstructure. The p-y curve has been used widely for the analysis of nonlinear relationship between the ground and structures, and various researches have conducted to apply the dynamic p-y curve for seismic design of group piles. This curve considers the interaction between the ground and structures under the dynamic load such as an earthquake. However the supported effect by the pile cap and the interaction by inertia behavior of superstructures. Therefore, the shaking table test was conducted to verify the effect of the change of the pile cap in group piles supporting superstructures embedded in sandy soil. The test condition is that the arrangement and distance between centers of piles are fixed and the length of the pile cap is changed for various distances between the pile cap side and the pile center. The result shows that the distance between the pile cap side and the pile center have an effect on the dynamic p-y curve and the effect of group piles.

• 한국노년학
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• v.32 no.3
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• pp.729-745
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• 2012

The purpose of this study is to review person-centered care models and the scientific evidence for the impact of person-centered care in U.S. nursing homes, and to analyze the applicability of person-centered care for Korean long-term care system. The most commonly recognized person-centered care models were Eden Alternative, Green House, and Wellspring model. The core components of the three models were autonomy, close relationships, homelike environment, and staff empowerment. Thirty eight empirical studies including 10 model testing studies and 28 studies to examine the impact of person-centered care interventions indicated generally positive outcomes in terms of residents, family, and staff/organization level. The authors analyzed the current situation in the Korean long-term care system with respect to the specific core constructs of person-centered care, and proposed applicable models and practical suggestions in consideration of Korean context. Lastly, future considerations regarding policy and research were discussed.

• Journal of Korean Tunnelling and Underground Space Association
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• v.25 no.3
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• pp.187-200
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• 2023

This study analyzed the seismic fragility of bored tunnels based on their surrounding conditions and suggested a representative seismic fragility model. By analyzing the existed seismic fragility models developed for bored tunnels, we developed weighted combination models for each surrounding conditions, such as ground conditions and depth of the tunnel. The seismic fragility curves use the peak ground acceleration (PGA) as a parameter. When the PGA was 0.3 g, the probability of damage exceeding minor or slight damage was 20% for depth of 50 m or less, 10% for depth between 50 m and 100 m, and 3% for depth of 100 m or more. It was also found that the probability of damage was higher for the same PGA and depth when the surrounding ground was rock rather than soil. The probability of damage decreases as the depth increase. This study is expected to be used for developing a comprehensive seismic fragility function for tunnels in the future.

• The Journal of the Korea Contents Association
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• v.15 no.1
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• pp.171-184
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• 2015

This study aims to explore the realities of life and the utilizing experience of housing improvement service among the vulnerable living in the indecent house. For this purpose of this study, we conducted in-depth interview with nine interviewees. As the result of this study, we figured out that the vulnerable living in the poor house had experienced psychological withdrawals, restricted of social activities, health problems, and feelings of insecurity. However, they could not afford to improve their houses because they were living below or near the poverty line. Local government provided the housing improvement service to cope with this problem. The people received this service gave positive reviews. Since their residential environment was improved, they felt easiness, strengthened social relationships, and expected a warm winter. Despite of 'thankful service', the housing improvement service had some limitations. Because of the limited budgets, full-scale construction services were unfeasible. Also we figured out it is necessary to make a change in housing policies for the people living in the poor houses. In the conclusion, we discussed and proposed the policies and practical suggestions.