• Journal of the Earthquake Engineering Society of Korea
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• v.7 no.2
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• pp.9-20
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• 2003

At present, the information on the foundation-structure interaction is lacking. As a result, the seismic performance evaluation of buildings seldom considers the effect of the foundation performance on the building responses. Recent earthquakes such as the 1993 Hokkaido Nansei-oki Earthquake(M=7.8), the 1994 Northridge Earthquake(M=6.7), the 1995 Hyogoken-Nambu Earthquake(M=7.2), and the 1999 Chi-Chi Earthquake (M=7.6) have shown that building damages are significantly affected by the degree of damage sustained by the building foundation and the interaction between the building and the foundation. This paper presents a nonlinear seismic analysis method for the seismic performance evaluation of reinforced concrete buildings which considers the pile foundation-structure interaction. The proposed method is applied to an actual building which was damaged during the 1993 Hokkaido Nansei-oki Earthquake. The result reveal that the method is able to predict the performance of the building.

• Journal of the Korean BIBLIA Society for library and Information Science
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• v.29 no.1
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• pp.277-298
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• 2018

This study aims to demonstrate the importance of information literacy instructions by showing effects of information literacy skills on critical thinking dispositions among high school students. We collected 761 survey responses from high school students and conducted multiple regression analysis to examine the relationships between the two variables. The findings show that (1) students' information search skills affect their pursuit of truth, openness, inquiring mind, and objectivity, (2) the information analytic skills influence the levels of pursuit of truth, openness, and objectivity, (3) the information presentation and delivery skills affect the levels of inquiring mind, organization, and self-trust, and, (4) the information evaluation skills influence the levels of pursuit of truth, openness, inquiring mind, organization, objectivity, and self-trust. However, students' synthesis and application skills of students did not affect their critical thinking dispositions. To sum up, we observed the influence of information literacy skills on critical thinking dispositions. The results of this study provide foundations for maintaining and developing information literacy instructions in school libraries.

• Journal of the Korean Geotechnical Society
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• v.15 no.2
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• pp.3-16
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• 1999

The objective of BMP( Barge Mounted Plant) project is to construct plants on mooring floating structures at sea. To analyze the pile behavior under mooring dolphins, generally, axial or lateral behavior of soil-pile system is evaluated by using a nonlinear subgrade reaction method which models the pile as a structural element and the soil as series of nonlinear springs along the depth. As a result, load-displacement curves at pile head can be solved by finite difference method and the equivalent stiffness of bottom boundaries of dolphin structure is evaluated. In this study off-shore site investigation was performed on the marine area of Koje Island and axial and lateral load transfer curves of the ground were modeled with depth. The subgrade reaction analysis was performed for piles under axial or lateral loadings, and the required penetration depth and section of the pile were determined. Subsequently, the spring boundaries under the dolphin structure could be modeled from the calculated load-displacement curve and then the dynamic response of the dolphin structure was analyzed reasonably by considering ground conditions. The analysis considering the stiffness of the soil-pile system has resulted in larger displacement amplitudes than those for rigid foundations. Furthermore, moment distributions of the casing were dependent on the soil-pile system so that deformable foundation induces the larger moment of top section of casing and the smaller moment of pile head.

• Journal of the Korean Geotechnical Society
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• v.27 no.7
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• pp.47-57
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• 2011

The p-y curve has been used to design pile foundations subjected to lateral loading. Although the p-y curve has a large influence on the pile lateral behavior, p-y curves have not been clearly suggested. In this study, the p-y curve of clay was evaluated for drilled shafts in marine deposits by using 3-dimensional numerical analyses. First, the optimization study was performed to properly determine boundary extent, mesh size, and interface stiffness. The numerical modeling in the study was verified by comparing the calculated and the pile loading test results. Then, the p-y curves of single and group piles were evaluated from the parametric study. The selected parameters were pile diameter, pile Young's modulus and pile head fixed condition for a single pile, and pile spacing for group piles. Finally, the p-multiplier was evaluated by comparing the p-y curves of a single pile and group piles. As a result, the p-multiplier at pile spacing of 3D was 0.83, 0.67 and 0.78 for the front, middle, and back row piles, respectively, and showed values similar to those of O'Neill and Reese (1999). For the pile group with pile spacing larger than 60, the group effect can be ignorable.

• Journal of the Korean Geotechnical Society
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• v.29 no.7
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• pp.17-36
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• 2013

In this paper, the empirical relations of skin friction and end bearing resistance with the results of site investigation in soft rock are proposed through the analysis of bi-directional pile load tests of rock socketed drilled shafts performed at large offshore bridge foundations and high-rise building projects (13 test piles in 4 projects). The site investigation and drilling for bi-directional pile load tests were performed at the centers of test piles, and f-w curves for skin friction and q-w curves for end bearing were plotted based on load-transfer measurements. From the above curves, the empirical relations of skin friction and end bearing resistance with the results of site investigation depending on the mobilized displacement are determined by multiple regression analysis and compared with previous studies. Since the f-w and q-w curves of rock-socketed piles in Korea show hardening behavior according to mobilized displacement, the developed empirical relations by the mobilized displacement are more reasonable than those of previous studies which could not consider the mobilized displacement and suggested the ultimate capacity with unconfined compressive strength only. Particularly, the developed equations correlated with unconfined compressive strength show the best correlations among the equations correlated with other parameters.

• Journal of the Korean Geotechnical Society
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• v.32 no.11
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• pp.5-19
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• 2016

This paper presents the results from three-dimensional finite element (FE) analysis undertaken to provide insight into the lateral behaviors of piled gravity base foundation (GBF) for offshore wind turbine. The piled GBF was originally developed to support the gravity based foundation in very soft clay soil. A GBF is supported by five piles in a cross arrangement to achieve additional vertical bearing capacity. This study considered four different cases including a) single pile, b) three-by-three group pile (with nine piles), c) cross-arrangement group pile (with five piles), and d) piled GBF. All the cases were installed in homogenous soft clay soil with undrained shear strength of 20 kPa. From the numerical results, p-y curves and thus P-multiplier was back-calculated. For the group pile cases, the group effect decreased with increasing the number of piles. Interestingly, for the piled GBF, the P-multipliers showed a unique trend, compared to the group pile cases. This study concluded that the global lateral behaviour of the piled GBF was influenced strongly by the interaction between GBF and contacted soil surface.

• Journal of the Korean Geotechnical Society
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• v.34 no.1
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• pp.5-16
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• 2018

In this study, seismic performance of geotechnical seismic isolation system capable of primary seismic isolation in the ground was evaluated. 1-G shaking table test was used to assess the performance of Teflon or steel slag as geotechnical seismic isolation systems installed beneath superstructure foundation. Response acceleration and response spectra were analyzed considering different input motions. The results were compared with those of fixed foundation structure without seismic isolation system. The steel slag-type seismic isolation system showed significant reduction in acceleration. The teflon-type seismic isolation system did not show significant effects on acceleration reduction in low-to-moderate seismicity condition, but it did show better effects in case of strong seismic condition. As input motion was transferred to the upper mass, the response spectrum of the fixed foundation structure was amplified in the short period range. In contrast, the response spectrum of the structure with seismic isolation using teflon or steel slag amplified in the long period range. It is found that the change of periodicity and the friction characteristics between isolation materials and foundations affected acceleration reduction.

• Journal of Korean Home Economics Education Association
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• v.31 no.3
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• pp.1-21
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• 2019

The purpose of this study is to develop a 'Healthy Couple Relationship' curriculum(plan) for high school home economics based on backward design. In this study, the content elements of 'Healthy Couple Relationship' were extracted through literature analysis, and the need for contents of 'Healthy Couple Relationship' was surveyed in 197 families of home economics teachers and 154 high school students. Based on this, the 'Healthy Couple Relationship' curriculum(plan) of high school home economics curriculum was developed as the backward design, and it was verified by the expert group. The results are as follows: First, when measured on a 5-point Likert scale, the mean scores of the need for content elements of 'Healthy Couple Relationship' was 4.39 for teachers, and 4.02 for students, respectively. The content elements of 'understanding dating violence' was 4.70 for teachers and 4.19 for students. Second, the developed 'Healthy Couple Relationship' curriculum consists of two templates, one for each unit, including curriculum goals, unit composition and unit goals, 8 learning subjects and content elements, evaluation plans including 24 lesson plans. In this study, it is meaningful to propose a "Healthy Couple Relationship" curriculum as an elective course in high school home economics curriculum in preparation for the high school credit system, and to lay the foundations for opening elective courses.

• Spatial Information Research
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• v.22 no.6
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• pp.67-79
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• 2014

These days open source softwares are being introduced and applied in many countries in the world. Especially, both government and private companies tend to become an spearhead in vitalizing the open source software. In this paper we try to check the degree of vitalizations in open source GIS software and to draw implications in vitalizing ecosystem of open source GIS software. Key players of open source GIS software ecosystem are government, private companies, academic and research institutes, and nonprofit foundations. Government does not have very little policies related to the investment and the support of open source GIS software. Private companies related to the open source GIS software are very few in the number and do not have any clear business model to make a profit. Academic and research institutes are weak in using the open source GIS software, which can be an major obstacle to cultivate software developers. OSGeo Korean branch, established in 2009, is the only nonprofit foundation in Korea which makes an effort to vitalize the open source GIS software, but its results are not very strong up to now in view of both quality and invigoration. In order to vitalize the open source GIS software ecosystem, lots of efforts of key players are needed. Especially, government efforts are very important because it can provide a trigger in vitalizing the open source GIS software ecosystem. The tasks that government should propel are R&D investment, test bed projects in the area of public sector, professional manpower training, and international cooperation and marketing.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.31 no.3D
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• pp.343-353
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• 2011

The unsignalized intersections in a community road in the city of Seoul have 3,753 traffic accidents(9%) of total 41,702 cases in 2008, not high in the occurrence rate of traffic accidents, but seem to have a quite high potential of accidents due to the unreasonable and insufficient operation of systems and facilities in the part of traffic foundations. In particular, the un-signalized intersections in a community road have an insufficient measure for safety as compared to the crossroads with signals, and there are few analysis of traffic accidents and domestic researches on the model of affecting factors. Our country also has no concept of passing priority in operating a crossroad without signals, differently from foreign countries, so the researches and safety measures for improving the safety of a crossroad without signals in a community road are urgent. Therefore, This study set out to analyze the road conditions, traffic conditions, and traffic environment conditions on unsignalized intersection, to identify the elements that would impose obstructions in safety, and develop a traffic accident prediction model to evaluate the safety of an unsignalized intersection using the correlation between the elements and an accident. In addition, the focus was made on suggesting appropriate traffic safety policies by dealing with the danger elements in advance and on enhancing the safety on intersection in developing a traffic accident prediction model for an unsignalized intersection.