• Geotechnical Engineering
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• v.5 no.1
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• pp.35-46
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• 1989

To analyse the end bearing capacity of a single pile in cohesionless soils, the mode of deformation due to a pile penetration has been intestigated through model pile penetration tests using acetone hardening and resin impregnation technique. A new mode of deformation has been assumed from the experimental results and a new solution compeying with the theory of spherical cal.its expansion has been proposed. The end bearing capacity according to the proposed solution is expressed as the product of the limit spherical cavity expansion pressure multiplied by a col.relation factor. The results has been compared with other solutions based on the theory of cavity expansion. From the comparison, the proposed solution is expected to provide a way to solve the problem of pile bearing capacity prediction based on the theory of cavity expansion which often has been criticized as giving higher value of pile bearing capacity than the actual value.

• Journal of the Korean Geotechnical Society
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• v.27 no.1
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• pp.5-16
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• 2011

This paper presents the results of a three-dimensional finite element analysis on load supporting mechanism of pile constructed above underground cavity in limestone rock formation. Considering a wide range of cavity conditions, the behavior of pile was studied using the bearing capacity, rock yielding pattern, stress distribution and deformation of pile head and the cavity. The results indicate that the load transfer mechanism of pile, rock yielding pattern and the reduction of bearing capacity of pile significantly vary with the location, size and length of cavity. Based on the results, graphical solutions defining the reduction of the bearing capacity with specific cavity conditions were suggested.

• Journal of the Korea institute for structural maintenance and inspection
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• v.14 no.3
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• pp.178-185
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• 2010

This paper presents the evaluation of foundation stability according to decrease of the foundation contact area on the ground. In order to carry out this research, the experimental and numerical studies are performed. In the experimental study, the carefully controled laboratory model tests are carried out with different foundation size and types. The model test results are analyzed and interpreted by analytical and numerical calculation in order to verify both results obtained from experimental and numerical studies. It is clearly found from the results that the foundation stability is considerably reduced when the foundation contact area ratio is less than 75%. This research may be very useful to develop the economical foundation type.

• The Journal of the Korea Contents Association
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• v.18 no.12
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• pp.197-207
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• 2018

This study analysis effect of social support and career maturity on readiness for independent living of run away youths using drop in center. This result peer support had more influence on preparing for independent living than in supporting the working class and career maturity had a huge impact on all the low-variables of preparing for independent living. Career maturity level for run away youths paly an important role in preparing for independent living just like general youths. On the base this study propose supporting system preparing for independent living, worker empowerment, drop in center's role establish for independent living.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.49 no.3
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• pp.167-174
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• 2021

Computational Fluid Dynamics (CFD) was performed under low-speed wind tunnel test conditions using a 29.7% scale model of the NASA common research model. A wind tunnel test was conducted to measure the aerodynamic coefficient of the CRM with Belly sting model support configuration at a low Reynolds number of 0.3×106 and it was compared with the aerodynamic coefficient of CFD analysis. In order to verify the validation of the analysis, a computational analysis under the conditions of the advance research was performed and compared. The interference effect of the Belly sting model support affected not only the fuselage but also the main and tail wings.

• Journal of the Korean Society of Propulsion Engineers
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• v.24 no.5
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• pp.56-64
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• 2020

A wind tunnel test of 29.7% scaled model of NASA Common Research Model was performed in small low speed wind tunnel. The wind tunnel model was fabricated in Aluminium in consultation with NASA Langley Research Center and AIAA Drag Prediction Workshop committee members. The static aerodynamic forces and moments were measured at a relatively low Reynolds number of 0.3 × 10⁶ due to tunnel capability limitations. Pitching moment of three types of model support(Fin sting, Blade sting and Belly sting) were compared. The pitching moment for corrected Belly sting and Fin sting were similar. The result of pitching moment for Blade sting was very small.

• Proceedings of the Korean Geotechical Society Conference
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• 1996.10a
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• pp.321-326
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• 1996

• 한국보건간호학회:학술대회논문집
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• 2004.05a
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• pp.165-166
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• 2004

• Membrane Journal
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• v.23 no.6
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• pp.425-431
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• 2013

This paper has studied the hydrophilizing effect of support on the performance of pressure retarded osmosis (PRO). The hydrophilicity of polyester support has been controlled with cellulose solutions. In order to investigate the effect of hydrophilizing of support, the performance test has been conducted with membrane which compose of active layer and support in absence of support layer. The active layer has been made by casting of cellulose tri-acetate (CTA) 1,4-dioxane solution (13 wt%) and combined with the hydrophilized support. The results show that water fluxes of PRO membranes with hydrophobic or hydrophilized support were measured $0.8L/m^2hr$ and $1.2L/m^2hr$ under $5kgf/cm^2$ pressure, respectively. However, water flux increase did not accord with hydrophilicity of supports treated by cellulose solutions. It is because the porosity and pore size of supports decrease as the cellulose concentration increases. This result confirms that both the hydrophilization of support and the maintenance of membrane porosity are important to enhance the performance of PRO membrane.

• Polymer(Korea)
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• v.38 no.6
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• pp.815-819
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• 2014

Scaffolds of tissue engineering should be biocompatible and biodegradable for cell attachment, proliferation and differentiation. In the various scaffold fabrication, 3D printing technique can make the three dimensional scaffold with interconnected pores for cell ingrowth. Polycaprolactone (PCL) is biodegradable polyester with a low melting temperature and has been approved by the Food and Drug Administration (FDA). In this study, PCL scaffold was fabricated by 3D bioprinting system and surface modification of PCL scaffold was controlled by NaOH treatment. Morphological change and wetability of NaOH-treated scaffold were observed by SEM and contact angle measurement system. The remnant of PCL treated with NaOH was measured by ATR-FTIR. In vitro study of scaffolds was evaluated with WST-1 and ALP activity assay. NaOH treatment of PCL scaffolds increased surface roughness, hydrophilicity, cell proliferation and osteogenic differentiation. These results indicate that NaOH-treated PCL scaffold made by 3D bioprinting has tissue engineered potential for the development of biocompatible material.