• Journal of the Korean Geotechnical Society
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• v.26 no.8
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• pp.27-37
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• 2010

Downdrag force develops when a pile is driven through a soil layer which will settle more than a pile. There is no obvious criterion for application of the current pile design method considering the negative skin friction. Therefore, in this study, numerical analyses were performed to investigate the behavior of a single pile subjected to negative skin friction and their results were used to determine the applicability of the current design method. Including three different sites in Song-do area and two different cases with friction pile and end bearing pile conditions, total six cases were considered. The load-settlement relationships and the neutral points were estimated for different end bearing conditions and the allowable bearing capacity of piles with negative skin friction was investigated through parametric studies. Based on the results showed that the negative skin friction made a major influence on the settlement of a pile and its stress. However the allowable bearing capacity may not be influenced by the negative skin friction. Compared with the allowable bearing capacity obtained from the ultimate bearing capacity with the safety factor of 3, the current design method with the safety factor of 3 underestimated the allowable bearing capacities regardless of the end bearing conditions. On the other hand, the current design method with the safety factor of 2 yielded reasonable results depending on the end bearing conditions.

• Journal of the Korean Geotechnical Society
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• v.24 no.1
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• pp.111-118
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• 2008

In the study a 2 dimensional model test was executed to grasp the effect of the taking load of equipments on the ground when improving a soft ground like dredging reclaimed ground. The static load and the dynamic load in the consolidated model ground was $0.02kg/cm^2,\;0.03kg/cm^2\;and\;0.04kg/cm^2$ respectively. After consolidating far two months by consolidation load of $0.02kg/cm^2,\;0.03kg/cm^2\;and\;0.04kg/cm^2$ respectively, the ultimate bearing capacity was $0.16kg/cm^2,\;0.19kg/cm^2,\;0.24kg/cm^2$ respectively. And the energy price of dynamic load test at the same point as the settlement of static load test indicated $E=336{\sim}945kg{\cdot}cm,\;E=252{\sim}780kg{\cdot}cm\;and\;E=323{\sim}727kg{\cdot}cm$ for each consolidation load. When the static load and the dynamic load operated at the same ground condition, the heaving quantity was bigger in the case of the dynamic load than in the case of the static load, and the horizontal displacement quantity the in the case of dynamic load was exhibited very deficiently compared to the quantity in the case of static load test.

• Journal of the Korean Geotechnical Society
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• v.25 no.11
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• pp.27-38
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• 2009

In this study, a series of 1 g shaking table model pile tests were carried out in saturated dense and loose sand to evaluate dynamic p-y curves for various conditions of flexural stiffness of a pile shaft, acceleration frequency and acceleration amplitude for input loads. Dynamic p-y backbone curve which can be applied to pseudo static analysis for saturated dense sand was proposed as a hyperbolic function by connecting the peak points of the experimental p-y curves, which corresponded to maximum soil resistances. In order to represent the backbone curve numerically, empirical equations were developed for the initial stiffness ($k_{ini}$) and the ultimate capacity ($p_u$) of soils as a function of a friction angle and a confining stress. The applicability of a p-y backbone curve was evaluated based on the centrifuge test results of other researchers cited in literature, and this suggested backbone curve was also compared with the currently available p-y curves. And also, the scaling factor ($S_F$) to account for the degradation of soil resistance according to the excess pore pressure was developed from the results of saturated loose sand.

• Journal of the Korean Geotechnical Society
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• v.23 no.2
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• pp.61-69
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• 2007

In this study, experimental analysis was performed about lateral load capacity and behavior of laterally loaded-bored piles for soil conditions and pile shape, i.e. cylindrical and taper piles. Also, Calibration chamber load tests were performed for cylindrical and taper piles considering the variations of relative densities and restraint stresses. According to the results of chamber tests, it was found that, while both vertical and horizontal stresses affect load-responses and ultimate lateral load capacity of laterally loaded piles, effect of the horizontal stress was larger than that of the vertical stress. Effect of lateral load capacity and behavior was relatively small compared to relative density and stress state of soils surrounding piles, but showed a little difference for soil conditions. From comparison between predicted and measured lateral load capacity, it was observed that predicted results differ significantly from measured results. This is mainly due to the fact that the effect of horizontal stress is not considered in the conventional prediction methods.

• Composites Research
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• v.20 no.3
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• pp.8-16
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• 2007

Bending collapse of light-weight square tubes used for vehicle structure components is a dominant failure mode in oblique collision and rollover of vehicles. In this paper bending performances of aluminum-GFRP hybrid tube beams were evaluated in relation with bending deformation behavior and energy absorption characteristics. Aluminum/GFRP hybrid tube beams fabricated by inserting adhesive film between prepreg and metal layer were used in the bending test. Failure mechanisms of hybrid tubes under a bending load were experimentally investigated to analyze the bending performance as a function of ply orientation and composite layer thickness. Ultimate bending moments and energy absorption capacity of hybrid tube beams were obtained from the measured load-displacement corves. It was found that aluminum/GFRP hybrid tubes could be converted to rather stable collapse mode showing excellent energy absorption capacity in comparison to the pure aluminum tube beams. In particular, the hybrid tube beam with $[0^{\circ}/90^{\circ}]s$ composite layer showed a large improvement by about 78% in energy absorption capacity and by 29% in specific energy absorption.

• Journal of the Korea Society of Computer and Information
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• v.14 no.3
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• pp.227-235
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• 2009

The ultimate goal of hotel corporations is to maintain their existence by securing competitive advantages over their competitors. In order to secure competitive advantages, they need to shed off the conventional paradigm of company management, which increasingly grows weaker as the industrial society turns into a knowledge-based one, and make effective use of knowledge, which is the core source of their wealth and competitiveness, in their management. Thus this study set out to identify knowledge management strategy to result in great management performance to hotel corporations. It also aimed to suggest specific action plans for them to do knowledge management efficiently based on the results. The causal relations between the knowledge management strategy and management performance were examined to figure out the former's influences on the latter. As a result, Two types of knowledge management strategy seemed to have positive(+) impacts on competitive advantages, but negative(-) impacts on financial performance.

• Journal of the Korean Society for information Management
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• v.39 no.1
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• pp.171-193
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• 2022

In contemporary society, the importance of 'Citizen Participation' has been recognized and actively used in various fields. Archives are also planning citizen participation activities according to the trend, but there is a limit to taking the form of passive participation activities such as participation in contests and donation of records. The ultimate purpose of this study is to prepare issues and specific action plans to induce more active citizen participation in domestic archives. To this end, first, previous studies related to citizen participation in the field of records management were reviewed, and terms and concepts were established. Next, advanced cases that are stably operating overseas were selected and analyzed from various aspects, and through this, specific program operation elements and pros and cons were identified. After that, the current status of domestic archives that have or are planning to engage in citizen participation activities was investigated to derive factors to be considered from a practical point of view when introducing the actual program. Based on this study, it is hoped that it will contribute to the establishment of a participating recording culture by designing and operating Citizen-Participating Programs suitable for individual archives.

• Journal of Aerospace System Engineering
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• v.16 no.1
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• pp.104-109
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• 2022

The bomb rack unit (BRU) installed inside the pylon serves to fix external attachments such as external fuel tank or external weapon, and also serves to separate external attachments in case of emergency. In particular, the load generated when the external attachment is separated from the BRU is called the punching load. In this study, we present the results of a structural static test performed to verify the structural integrity of the pylon under the BRU punching condition acting on it. In the structural static test report, we present the implementation method for the separation load of the external attachment and the test profile for the BRU punching load condition, and compared the error between the load input signal and the feed-back signal to determine the appropriateness of load control in each test. Furthermore, we compared the strain results obtained in the numerical analysis and structural test at the main positions of the specimen. As a result, it was shown that the load of the actuators were properly controlled within the allowable error range in each test, and the numerical analysis effectively predicted the test result. Finally, through structural static tests conducted by design limit load and design ultimate load, we verified that the aircraft pylon dealt with in this study has sufficient structural strength for external attachment separation condition.

• Journal of Korean Philosophical Society
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• v.124
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• pp.295-320
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• 2012

Greek myth is a play of imagination. It represents world with magic eye. The Greek myth of Homer and Hesiod is the story of gods. But it is the world of imagination which was produced to understand the origins and the causes of natural phenomena with the symbolic factors. It is the frame with which we understand the destiny of human beings. As a world of imagination, Myth is not a total fiction but a symbolically revived world with magic eye. Myth is a play which represents the world with imagination. And it is a play which projects new world yet not exists. Myth is the world of free play with reproduction and imagination. Heraclitus elucidated the structure and change of world with the metaphor of play. He tried to define the meaning of being with play. The play is the clue of elucidating the meaning of being. On play the whole world is reflected. He expressed the world has no ultimate end and is changing endlessly. Philosophical speculation understands the world with the metaphor of play. Metaphor is correlated with the philosophical eye which view the world totally. The human beings are happy when they concentrate upon play. The rule of real world doesn't go in the world of play. They have their own rule which goes in the world of play. Ancient mythologists and pre-socratic philosophers dreamed the life free from the restriction of the nature.

• Asia-pacific Journal of Multimedia Services Convergent with Art, Humanities, and Sociology
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• v.6 no.2
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• pp.169-178
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• 2016

The number of people with disabilities is increasing recently in Korea, in particular the proportion of children with disabilities is approximately above 5%. While there are many studies focusing on satisfaction of payment policy due to increased concern about children with disabilities, the studies on comparison and the effect factor of user satisfaction depending on the cash and voucher are not sufficient. Based on the need to recognize and research this issue, the ultimate goal of this study is to lead to implications for the payment policy by investigating user satisfaction depending on the type of payment of policy on children with disabilities. The result that analyzes the effect of general characteristics on user satisfaction shows that in case of in-cash, children and the degree of disability affect user satisfaction. In the case of voucher, the gender of parents, the degree of disability and the average income affect it. The implication of this study suggests practical implication and policy implication. Implications of the study is that provide a customized service considering general characteristics. Second, It needs to extend the range of amount of payment of in-cash. Third, extend and pay the amount of in-cash, and the service of voucher. Fourth, provide low-income group(including public aid recipients and near poverty group) with voucher to ease financial burden.