• KSTLE International Journal
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• v.1 no.2
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• pp.107-112
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• 2000

In case of the limitation of Deep RIE fabrication far Micro Gas Turbine, bearing aspect ratio is limited in very small value. The characteristics such as pressure distribution, load capacity and non-linearity of a short bearing of L/D=0.083 and a conventional bearing of L/D=1.0 with coupled boundary effects are investigated for Micro Gas Turbine bearings. The coupled effect was analyzed by mass conservation at coupled end area. The results, increasing load capacity and non-linearity due to the coupled effect of thrust and journal bearing, are obtained and the selection of journal bearing type is discussed.

• Geomechanics and Engineering
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• v.8 no.2
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• pp.221-235
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• 2015

A series of laboratory model tests were conducted to investigate the effects of buried pipes location on the bearing capacity of strip footing in cohesionless soil. The variables examined in the testing program include relative density of the sand, loading rate of tests, burial depths of pipe and horizontal distance of pipe to footing. The test results showed a significant increase in bearing capacities when embedment ratio of pipe and horizontal distance of pipe to footing were increased. Based on the test results, it can be concluded that the location of pipes and relative density of sand are main parameters that affect the bearing capacity of strip footing. However, loading rate has not considerable effect on bearing capacity.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 2000.11a
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• pp.243-249
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• 2000

In case of the limitation of Deep RIE fabrication for Micro Gas Turbine, bearing aspect ratio is limited in very small value. The characteristics such as pressure distribution load capacity and non-linearity of a short bearing of L/D=0.083 and a conventional bearing of L/D=1.0 with coupled boundary effects are investigated far Micro Gas Tlubine bearings. The coupled efffect was analyzed by mass conservation at coupled end area. The results, increasing load capacity and non-linearity due to the coupled effect of thrust and journal bearing, are obtained and the selection of journal bearing type is discussed.

• Proceedings of the Korean Geotechical Society Conference
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• 2005.03a
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• pp.705-712
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• 2005

Among soft ground treatment methods with granular soil used in domestic, the sand compaction pile method has been utilized greatly, but, as a result of exhaustion of sand and increase of unit cost, a necessity of an alternative method is suggested. In this study, the static load tests for group crushed-stone compaction piles which were constructed at in-situ site were performed. Pile diameter was 700mm and area of loading plates were changed. The static load tests of single and group piles were performed for area replacement ratio of 20, 30 and 40%. Based on test results, bearing capacity of group crushed-stone compaction pile were estimated. The more both single pile and group pile increase, the more yield bearing capacity tended to increase. Also, the yield bearing capacity of a group pile is about 50% less than the yield bearing capacity of a single pile. If the ground reinforced with the crushed-stone compaction pile is replacement ratio of $20{\sim}40%$, RIYB of both single pile and group pile increases qualitative tendency of linear more than original ground

• Journal of the Korean Geotechnical Society
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• v.35 no.3
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• pp.17-24
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• 2019

The purpose of this study is to understand the characteristics of bearing capacity of shallow foundation on the grounds. We made a comparative study of existing bearing capacity theory, based on the three-dimensional finite element analysis with a variety of conditions such as ground condition, foundation scale and foundation shape. In the finite element analysis, the ultimate bearing capacity showed a gradual convergence in the form of exponential function or logarithm function according to the foundation scale. Although the shear strength increased, the bearing capacity tended not to increase but change linearly. In the results of comparative study of existing bearing capacity theory, bearing capacity ratio ($q_{u(FEA)}/q_{u(theory)}$) of pure sand has the outcome closest to those of the Terzaghi method. Pure clay turned out to be about 0.4~0.6 while normal soil was changed in a range of 0.3~1.3. As shear strength is increased, the results turned out to be less than 1.0. Bearing capacity ratio ($q_u/q_{u(1.0)}$), normalized at 1.0m bearing capacity, was about 35%, 15% and 5% of theoretical formula under the condition of ${\phi}=25^{\circ}$, $30^{\circ}$ and $35^{\circ}$ of pure sand; no scale effect was found with pure clay and the normal soil with lower soil strength level showed less than 10% of the theoretical formula of pure sand. Bearing capacity ratio of each case, in accordance with, the shear strength increase, was largely influenced by the internal friction angle. Shape factor of bearing capacity ratios classified by foundation shapes have different results according to the shapes; the shape factor of circular foundation is 1.50, square foundation is 1.30, rectangular and continuous foundations are 1.1~1.0.

• Journal of the Korean Geosynthetics Society
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• v.19 no.1
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• pp.65-73
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• 2020

This study describes the evaluation results of pile length ratio and N value on the bearing capacity of drilled shafts in cohesionless soil. The bearing capacity ratio in Meyerhof's formula is affected only by the length ratio, and it is equally evaluated a sharing ratio of the end bearing capacity and the skin friction. NAVFAC's formula shows that the pile length influences both end bearing capacity and the skin friction, but pile length is also found to be a more influence factor on the end bearing capacity. Especially, it was found that the effect of pile length factor was larger than the effect of N value and pile diameter. FHWA's formula was evaluated to reflect the influence factor by skin friction more positively than other formulas at calculation the bearing capacity. It was also confirmed that the influence of the skin friction is larger when the ultimate bearing capacity is evaluated.

• Proceedings of the Korean Geotechical Society Conference
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• 2009.09a
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• pp.1001-1010
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• 2009

The study that unconfined compression strength of intact rock which is the most important factor to determine the bearing capacity effects discontinuities in rock mass has been carried out actively so far. However, the study which is related to lithological characters such as vesicle which is one of the primary characteristics of Basalt has barely been conducted. On this study, We have analyzed the correlation-ship between vesicle and unconfined compression strength and the effect on the bearing capacity, based on the reviewing on the changes of unconfined compression strength as the amount of vesicle of Basalt. It is impossible to analyze the amount of vesicle of Basalt as measuring unit. So it was analyzed by the ratio of the core sample's surface area and another area that vesicle takes up. Also, unconfined compression strength was calculated by point load test and unconfined compression strength test. The analysis shows that vesicle area ratio and unconfined compression strength have the exponential relationship and vesicle area ration is the factor to determine the bearing capacity of Basalt. It is considered that the reliability of calculating of the bearing capacity of Basalt will be improved as we study the correlation-ship between the vesicle area ratio and rock mass grade hereafter.

• Journal of the Korean Society of Physical Medicine
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• v.9 no.3
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• pp.315-324
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• 2014

PURPOSE: This study aimed to determine the correlation of weight bearing ability at the affected side with balance and gait abilities for the development of pressure biofeedback based equipment to stroke patients. METHODS: This study included 35 patients with stroke patient. The tests were conducted to determine the weight bearing ratio while pushing a step forward the affected side, static balance ability using the total length of COP(Center of pressure), sway velocity of COP, COP velocity at the X and Y axis. Functional reaching test (FRT), berg balance scale (BBS) were used to assess the dynamic balance ability and timed up and go test (TUG), 10m walk test (10mWT) were used assess the gait ability respectively. In order to determine the correlation between measured variables, bivariate correlation analysis was conducted. RESULTS: A significant correlation of the weight bearing ratio were shown with COP total length and velocity(r=-.34), Y-axis velocity(r=-.39), FRT(r=.42), BBS(r=.54), TUG (r=-.39), and 10m walking test (r=-.42). CONCLUSION: This study result showed that as patients with stroke had more weight bearing ratio at the affected side, not only their static and dynamic balance abilities increased more but also functional gait ability improved more. These results mean that, to improve stroke patients' static, dynamic balance ability and gait ability, weight bearing training with the affected side foot placed one step forward necessary for gaits are important.

• Advances in concrete construction
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• v.10 no.4
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• pp.289-299
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• 2020

A reliability analysis of the axial compressive load bearing capacity of postfire reinforced concrete (RC) columns strengthened with carbon fiber reinforced polymer (CFRP) sheets was presented. A 3D finite element (FE) model was built for heat transfer analysis using software ABAQUS. Based on the temperature distribution obtained from the FE analysis, the residual axial compressive load bearing capacity of RC columns was worked out using the section method. Formulas for calculating the residual axial compressive load bearing capacity of the columns after fire exposure and the axial compressive load bearing capacity of postfire columns retrofitted with CFRP sheets were developed. Then the Monte Carlo method was used to analyze the reliability of the axial compressive load bearing capacity of the RC columns retrofitted with CFRP sheets using a code developed in MATLAB. The effects of fire exposure time, load ratio, number of CFRP layers, concrete cover thickness, and longitudinal reinforcement ratio on the reliability of the axial compressive load bearing capacity of the columns after fire were investigated. The results show that within 60 minutes of fire exposure time, the reliability index of the RC columns after retrofitting with two layers of CFRPs can meet the requirements of Chinese code GB 50068 (GB 2001) for safety level II. This method is effective and accurate for the reliability analysis of the axial load bearing capacity of postfire reinforced concrete columns retrofitted with CFRP.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.24 no.11
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• pp.2680-2687
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• 2000

The Reynolds equation, incorporating Elrods cavitation algorithm, is discretized on a rectangular grid in computational space through coordinate mapping in order to accurately analyze a herringbone grooved journal bearing of a spindle motor in a computer hard disk drive. The pressure distribution and cavitation area are determined by using the finite volume method. Predicted results are compared to experimental data of previous researchers. It was found that positive pressure is developed within the converging section of the bearing and that a cavity occurs in the diverging section. Cavitation has been neglected in the previous analysis of the herringbone grooved bearing. Load capacity and bearing torque are increased due to the increased of eccentricity and L/D and the decrease of the grooved width ratio. The maximum load capacity was found to occur at a groove angle of 30 degrees while bearing torque remains constant due to the variation of the groove angle. The cavitation region is significantly decreased with the inclusion of herringbone grooves. However, the region increases with the increase of the eccentricity, L/D, groove angle and the rotational speed and the decrease of the grooved width ratio.