• 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.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.37 no.1
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• pp.83-91
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• 2017

In case of estimation of settlement for the piled-raft foundation, it is necessary to consider interaction among raft, piles and soil. But, simple analytic methods usually are not applicable to considering this complicated interaction. In this study, a computer-based approximate analytic method, HDPR, was developed in consideration of above mentioned interaction in order to analysis of settlement for the piled-raft foundation. The finite element method was applied to raft analysis by means of the Mindlin plate theory, and soil and piles were modeled as springs which were connected with their raft. The linear spring which can consider multi layered soil and the non-linear spring were applied to soil springs and pile springs, respectively. The raft-piles-soil interaction was reflected to each spring. In order to verify the developed analytic method, it was compared and analyzed with 3D FEM analysis, existing approximate analytic method and site monitoring data. As a result, the developed analytic method showed reasonable results of settlement estimations of raft and piles for each case. From a practical point of view, it is confirmed that this analytic method is able to apply for analysis and design of the piled-raft foundation.

• Journal of The Korean Association For Science Education
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• v.21 no.2
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• pp.342-356
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• 2001

Integrated science for high school is required in the present Korean National Sixth Curriculum and the Seventh Curriculum which will be effective in 2002. Currently, most science teachers in secondary school have concerns about teaching integrated science subjects and this continues to raise a significant problem for practical implementation of integrated science education in schools. In this paper, we discuss two reasons for these concerns that our analysis revealed: 1) Science teachers do not understand how to implement integrated science education and 2) there are insufficient teaching-learning materials supporting integrated science. Three different approaches to integration that have been suggested to overcome the problem of implementation are outlined here. They are the knowledge centered, social problem centered, and individual interest centered approaches. Reported here are the first two steps we undertook in preparation for testing the relative effectiveness of these approaches. First, we analyzed the content of the Korean Sixth and Seventh National Science Curricula, seven Korean integrated science text books, the American National Science Education Standards, and the American Association for the Advancement of Science Benchmarks looking for common themes. We identified in the analyzed materials the common themes: energy conservation, energy transformation, energy transport, energy degradation. We then used their energy related content to organize sets of concept structures, one set for each of the three approaches. These concept structures will provide the foundations for the development of integrated teaching-learning energy plans to be used in our research into the effectiveness of the approaches.

• Journal of the Korean Geotechnical Society
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• v.36 no.7
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• pp.5-14
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• 2020

Kansai International Airport (KIX) was opened in September 1994. Although 26 years have passed since the completion of the first island, long-term settlement is still in progress. This settlement occurs in the Pleistocene layer. For it is not easy to determine the permeability of the Pleistocene sand layer because the thickness and the degree of fine content in the horizontal direction are constantly changing. In addition, it is also a difficult to predict the interactive behavior of the ground due to the construction of the second phase island adjacent to it. In order to solve this problem, a two-dimensional finite element analysis considering elasto-viscoplastic was performed to evaluate the long-term deformation, including the interactive behavior of the alternating Pleistocene foundation due to the construction of two adjacent reclaimed islands. In general, two-dimensional analysis can be used when a section can represent the entire sections. However, Kansai Airport is an artificial reclaimed island so two-dimensional analysis cannot solve the problem such as the stress deformation in the corners of the island. Additionally, the structure of the actual sub-ground through physical exploration is non-homogeneity and its thickness is also not constant. Therefore, there are limitations for the two-dimensional analysis to explain the phenomena. That is, three-dimensional analysis is strongly required. Due to these demands, the author extended the existing two-dimensional program capable of elasto-viscoplastic analysis to three-dimensional and completed the verification of the three-dimensional program developed through one-dimensional consolidation analysis. In order to demonstrate the validity of the developed 3D program that has been verified, an analysis is performed under the same analysis conditions as the existing research using a two-dimensional program. The effectiveness of the developed 3D numerical analysis program was demonstrated by comparing the analysis results with the 2D results and actual measurement data.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.36 no.2
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• pp.46-53
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• 2018

The background of this study was to consider regenerative environmental characteristics and develop foundations for conceptual grounds and applications in embodying sustainable garden designs demanded in our age. In doing so, this study aimed to have a conceptual understanding of Clement's garden theory influenced by Robinson's naturalistic distinction and compared it with Robinson's wild garden, and the results are as follows: First, for Clement, garden design included an ecological process to settle in the target site as aesthetics of space being formed by the movement of plants. In this sense, making a 'garden in motion' implies to design possibilities to adapt to nature based on trust in it and allow plant seeds not to be planned but to naturally go and find appropriate habitats. Second, the views to wildness can be separated into microscopic and macroscopic views and each has its own expressive characteristics. Robinson's gardens are small and subordinate and play mollification functions for existing spaces. On the contrary, Clement's gardens are the subject of the space, represent macroscopic strategies, and have top-down approaches embodied as infrastructure to play central roles in the ecology. Third, Robinson's and Clement's views to the operation of garden spaces acknowledge the inseparable relationship between nature's autonomy and gardens' wildness and deliver a value that the preservation of nature is a prerequisite to coexistence with the life we desire. Their gardens are analogized by interventions of environmental possibilism and ecological standpoints mediated by plants based on the perspective of environmental determinism.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.2
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• pp.718-727
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• 2011

This research aims to empirically investigate into the relationship between venture entrepreneurs' social network and their social competence to utilize the network, which is known to help overcome the weaknesses of small-and-medium-sized ventures. An analysis was made of SEM set up with 211 entrepreneurs' responses, and the following are the findings from the analysis. First, venture entrepreneurs' networking ability has a significant, strong and positive effect on weak tie of their social network(${\beta}$=.527, C.R.=3.626), strong tie(${\beta}$=.594, C.R.=3.969), and the network centrality(${\beta}$=.418, C.R.=4.884). Second, their social astuteness also has a significant and positive effect on weak tie(${\beta}$=.192, C.R.=1.701), strong tie(${\beta}$=.269, C.R.=2.509) and the network centrality(${\beta}$=.228, p=2.283). Third, their interpersonal influence has a significant but negative effect only on strong tie(${\beta}$=-.264, C.R.=-1.862) and the network centrality(${\beta}$=-.394, C.R.=-2.914). Lastly, their apparent sincerity has no significant effect on the subordinate factors of social network. This research has not just empirically analyzed the relationship between the entrepreneurs' social network and their social competence. But also, results of the research provide practical and detailed information to entrepreneurs of small and medium ventures. Moreover, the research is significant in that it has suggested and empirically analyzed the concept of political competence, which is a concrete substance of social competence, and that it has offered theoretical foundations for future researches, which will tackle the issue of the entrepreneurs' competence in the sphere of entrepreneurship.

• Journal of the Korea institute for structural maintenance and inspection
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• v.15 no.1
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• pp.198-208
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• 2011

When a structure which has relatively low load constructs on soft clay, the bearing capacity of the ground will be improved by sand overlying clay. In this condition, verifying the bearing capacity is difficult from the P.B.T etcetera in the in-situ. So, it is needed to estimate precise bearing capacity in the design process. In this study, 2-dimensional chamber tests and FEM analyses are conducted to evaluate behavior of bearing capacity for shallow foundations on a sand overlying clay. Because depth ratio H/B and bearing capacity ratio $q_c/q_s$ are selected as main factors, height of a sand, undrained shear strength of a clay and width of a loading are designated as variables. Results from chamber tests are very similar with those of FEM analyses. And it shows that punching shear mechanism is more suitable than the equation of Okamura et al.(1998). To make continual application of load spread mechanism, the equivalent load spread angle is proposed for H/B and $q_c/q_s$. Also, the linear regression equation of critical depth ratio Hf is suggested for $q_c/q_s$.