• Journal of the Korea Concrete Institute
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• v.14 no.1
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• pp.83-91
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• 2002

A common form of construction for apartment buildings consists of walls and coupling elements. But, the structural behavior of coupling elements are very complex and affected by the properties of coupling elements. The objective of this study is to estimate the behavior of coupling elements in wall-dominant systems. For the purpose of this study, two wall-slab specimens and two wall-beam specimens were tested. The specimens with different reinforcement layouts were subjected to reversed cyclic loading, consistent with coupling action, with increasing imposed inelastic deformations. From the results of this study, 1) in coupling slabs, the stresses were not uniform across the width, 2) the effective width of coupling slabs was found smaller than that of predicted from previous studies, 3) diagonally reinforced coupling beam with slab showed larger ductility and more amount of energy dissipation to be attained compared with conventionally reinforced coupling beam.

• The Journal of Korean Academy of Prosthodontics
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• v.34 no.4
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• pp.699-721
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• 1996

브로네마르크가 골유착성 임플랜트를 소개한 이래로, 현재 골유착성 임플랜트에 의한 치료는 안전하고 안정적인 방법으로 여겨지고 있다. 골유착성 임플랜트를 이용한 초기의 치료는 무치악 환자의 저작기능 회복에 중점을 두어 왔다. 그러나 현재는 환자와 시대의 요구에 따라서 심미성이 주요한 관심사가 되었다. 그래서 표준 지대주보다 더 심미적인 지대주 시스템들이 개발되었다. 다양한 직경의 임플랜트 고정체에 관한 임상가들의 요구에 의해 직경 이 큰 고정체가 생산되기 시작했으며, 5mm의 직경을 갖는 고정체가 그 예이다. 골유착성 임플랜트를 사용하여 보철치료를 할 때, 골과 고정체의 계면은 보철물과 지대주에 가해지는 교합력을 인접골에 전달하게 되며, 이것은 계면에 생물학적인 반응을 야기할 수 있다. 임플랜트의 형태는 골흡수와 같은 바람직하지 않은 반응을 일으키지 않도록 고안되어야 하며, 임플랜트 자체가 교합력을 견딜 수 있어야 한다. 그러므로 골유착성 임플랜트 시스템을 임상에 사용하려고 할 때 이것의 생역학적 분석은 반드시 필요하다. 본 연구에서는 삼차원 유한요소분석적 방법을 사용하여 3.75mm직경을 갖는 고정체에 표준 지대주, 이세티콘 지대주, 마이러스콘 지대주를 연결한 모델과 5mm 직경을 갖는 고정체에 표준 지대주를 연결한 모델에 각각 수직하중, 경사하중, 수평하중을 가했을 때의 응력분포를 비교하였다. 본 연구의 결과는 다음과 같다. 1. 모든 모델에서 금나사의 경부, 금원주, 지대주에 응력의 집중이 일어났다. 2. 임플랜트 고정체에서는 고정체 상방 2/3, 그리고 지대주와 접촉하는 고정체 상면에서 응력의 집중이 관찰되었다. 3. 골에서는 상부 피질골에 응력의 집중이 관찰되었으며, 해면골에서는 두드러진 응력의 집중을 보인 부위는 없었으나 고정체의 근단부 주위 해면골에서의 응력값이 비교적 높았다. 4. 5mm 직경의 고정체를 사용하지 않은 모델 중에서, 표준 지대주를 사용한 경우가 가장 응력분산에 유리하였으며 마이러스콘 지대주를 사용한 경우가 가장 불리하였다. 5. 3가지 하중 조건하에서 수평하중과 경사하중의 경우가 수직하중의 경우보다 더 높은 응력값이 관찰되었다. 6. 응력값은 골에서보다 임플랜트 내부에서 훨씬 높았다.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.1
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• pp.459-467
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• 2016

Recently, new open-cut modular construction method, which is built within a 5~7m depth below the road, was proposed for the near-surface transit system to ensure the economic feasibility of underground structures. In this paper, the precast modular construction method was developed for the low-cost and rapid construction of underground structures. For the experiment on the flexural performance of the modular slab connections, a total of eleven specimens were fabricated according to the test variables; section shape, joint type, lap length, and transverse reinforcement. The test results were compared with those of the specimens without loop joints. To verify the performance of the slab connections, the 4-point loading tests of precast RC members with loop joints were conducted. As a result of the test, the flexural performance of the half-depth specimens with a 200mm lap length of loop joints were confirmed to be similar to those of the specimens without joints.

• Korean Journal of Childcare and Education
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• v.11 no.4
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• pp.189-210
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• 2015

This study's aim was to find a patterns of network dynamics focused on multicultural education contents within the teacher's guide books which are based on national kindergarten curriculum. It was analysed that the 43 guidebooks(2009 Educational activities and materials guidebooks for kindergarten, 11 and the Nuri curriculum teacher guidebooks for the age of 3-5, 32) were analysed using the UCINET 6 program with multicultural education contents frameworks. The findings were as follows: First, multicultural contents' density is connected to life theme of the Nuri curriculum was higher than the 2009 kindergarten curriculum. And life theme with high connectivity was 'I and my family' in the 2009 kindergarten curriculum and 'animals, plants and nature'(3 years old), 'kindergarten and friends' & 'I and my family'(4-5 years old) in the Nuri curriculum. Second, the highest connection content was 'having interests in culture' & 'knowing similarities and differences' in the 2009 kindergarten curriculum, and 'having interests in culture' & 'promoting a sense of community' in the Nuri curriculum. Finally, multicultural education for young children according to the national educational curriculum transition was changed from 'identity' to 'interaction and cooperation'. It means that the Nuri curriculum is more focused on international knowledges and competencies as a world citizen. It suggests the directions for multicultural education for young children in the future.

• Journal of Korean Society of Steel Construction
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• v.28 no.6
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• pp.467-476
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• 2016

For the connections between modular units in modular buildings, the bolted joints with connector plates are used commonly. The strength of structure is determined by the weakest part of structure and the connections may be weaker than the members being joined. Therefore, to check the safety of modular building, the structural performance of connections between modular units as well as that of beam-to-column connections should be evaluated. In this study, the behavior of module to module connection with straight and cross shaped connector plates is investigated by lateral cyclic tests according to KBC2009 0722.2.4 which shall be conducted by controlling the story drift angle in the width and the longitudinal direction respectively. All of test results generally show the stable ductile behavior up to 0.04rad drift levels and the tests in longitudinal direction show a superior energy dissipation per cycle in each of the load steps. However, the straight shaped connector plates have the degradation of stiffness with cyclic loading and the larger drift angle of column than the cross shaped connector plates.

• Journal of the Economic Geographical Society of Korea
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• v.20 no.1
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• pp.49-69
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• 2017

The crisis of western welfare states and the spread of neoliberalism opened up the debate on community question and paid attention to community to cope with diverse social crises. There has been increasing recognition for the need to see World Heritage in terms of place and local community which had formed it rather than an object for conservation separated from the place where it is located. In addition, the conservation and use of cultural heritage can lead to the region's sustainable development and in turn is possible with the region's overall development. However, the Operational Guidelines for the Implementation of the World Heritage Convention does not specify the definition and geographic extent of community. This paper considers place-based communities, Sahachons and religious communities, Sindohoes of seven Buddhist monasteries in preparation for inscription on the UNESCO World Heritage List, and analyzes social networks of these two types of communities to see their consistency with their general characteristics. Social networks analyses indicates that some monasteries show significant differences between Sahachons and Sindohoes, but others do not. This result implies that communities should be seen as processes of constantly reconstituting their features and boundaries under their specific surroundings which are also in constant changes, thus requiring empirical studies.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.1
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• pp.129-137
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• 2020

In designing a high strength bolted beam splice using steel for building structures, it is necessary to present the appropriate steel grade selection criteria for how to determine the cover plate steel grade. This study examined the difference in tensile behavior according to the steel grades through static tensile tests simulating the beam member high strength bolt joints flange. For this purpose, the specimens were designed and fabricated with the main variables, such as the thickness, steel grade and the strength of flange and cover plate, which are expected to affect the splice strength and behavior. The tensile test results for a total of 48 specimens showed that the tensile-load capacity exceeded the design tensile strength applied with a nominal strength of steel in all specimens. When the design strength of the cover plate exceeded 1.25 times that of the flange plate, the flange plate governed the behavior of splice. The change in maximum tensile load due to the change in flange steel grade is not very large, but there is a difference in deformation. The test results confirmed that the steel grade and thickness of the cover plate were the main factors affecting the beam splice behavior.

• Journal of the Korea institute for structural maintenance and inspection
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• v.26 no.3
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• pp.84-91
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• 2022

In this study, an experimental study was conducted to analyze the hysteresis behavior according to the steel fiber aspect ratio and volume fraction of diagonally reinforced concrete coupling beams under to cyclic loading. The aspect ratio and volume fraction of the steel fibers were set as the main variables, and 4 specimens were fabricated in which the amount of transverse reinforcement of the coupling beam suggested in the domestic building structural standard was relaxed by about 53%. In the experiment, cyclic loading experiments were performed in the displacement control method in accordance with ACI 374.2R-13, and as a result of the experiment, it was found that all specimens containing steel fibers exceeded the nominal shear strength suggested by the current structural standards. As the aspect ratio of the steel fibers increased, the steel fibers prevented the buckling of the diagonal reinforcement, and the bridging effect of the steel fibers held the crack surface of the concrete. The shear strength, stiffness reduction and energy dissipation capacity of the specimens containing steel fibers were superior to those of the Vf0 specimens without steel fibers. Therefore, it is judged that the steel fiber reinforced concrete can relieve the details of the transverse reinforced.

• Journal of Dental Rehabilitation and Applied Science
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• v.24 no.1
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• pp.77-89
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• 2008

The purpose of this study was to evaluate internal conical abutment sinking and fitness according to the loading condition. In this study, Alloden implant fixture and two abutment(conventional, FDI) systems were used. Each abutment was applied 1 time of finger force, 3 times of malleting force, 5 times of 20kg and extra several times to the fixture until the amount of abutment singking showed no change. Then, the length of abutment to fixture which was binding lightly with no pressure state was measured by Vernier caliper. After loading application, the length was remeasured and the amount of sinking was calculated. The implant was buried in unsaturated polyester (Epovia, Cray Valley Inc. Korea) for making a comparison between the change of length and fitness of abutment-fixture connection part. Then All samples were cross-sectioned with high speed precision cut-off(accutom-5, Struers, Denmark). Finally, The result were observed and analyzed using FE-SEM (field emission scanning electron microscopy).

• Journal of the Korea institute for structural maintenance and inspection
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• v.16 no.2
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• pp.49-57
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• 2012

Recently, in field of bridge construction, modular technology has been studied to reduce construction period. However, main stream of the study is limited to the pier, girder and deck of bridge, which are huge or main members. Studies on incidental facilities like concrete barrier is out of sight. Thus, in this study, connection system of concrete barrier was developed to apply to modular bridges and static experiment was performed in order to verify structural capability of proposed system. Variables of experiment are composed of bolt direction such as vertical and horizontal. The experimentation due to the designed variables was conducted by comparison with a standard concrete barrier, which is a traditional barrier. As a result, vertical joint way of the bolt showed nearly identical structural performance and healthy to standard specimen's. it can be applied to modular bridges.