• Land and Housing Review
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• v.2 no.2
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• pp.189-194
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• 2011

To reinforce bearing capacity-changed section or different foundation in the same building, empirical or simple tools have been used. To solve this problem, we suggest the analytical solution that can evaluate and reinforce the stability of foundation. To estimate the effect of reinforcement by replacement in different foundation, soil stiffness evaluation method taking into account the influence factor with respect to depth beneath the foundation need to be applied. In this paper, graphs and relevant formulae are suggested to calculate equivalent soil reaction coefficient showing the effect of reinforcement by crushed stone and lean concrete replacement.

• Journal of the Korean Geotechnical Society
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• v.35 no.12
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• pp.35-44
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• 2019

In this study, the axial stiffness of reinforcing piles (K_vr) for the vertical extension remodeling structures was estimated through 3D finite element analysis. In the computation of the minimum required axial stiffness of reinforcing piles, proposed maximum axial stiffness of old and deteriorated existing piles (K_ve) based on theoretical and experimental approaches will be applied. Through this, the required increase rate of axial stiffness of reinforcing piles in order to support the increased structural loading was proposed for end-bearing and friction piles by different slenderness ratio (L/D). The numerical model was validated by comparing the computed results with actual field measurements. Based on the computed results, it was concluded that the end-bearing reinforcing pile needs 44% - 67% increase in axial stiffness to deal with the deterioration of existing piles and support the additional structural load due to vertical extension remodeling.

• Journal of the Korean Geotechnical Society
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• v.21 no.10
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• pp.73-83
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• 2005

Recently, foundation designs based on piled raft concept have been increasing, where the piles are required not to ensure the overall stability of the foundation but to act as settlement reducer. When a concrete track is constructed on soft ground, excessive settlements may occur, while it rarely has bearing capacity problems. In this case, the settlement of the concrete track may be effectively reduced by arranging a small number of small-diameter piles beneath the track. This paper presents the effect of pile installation on the reduction of concrete track's settlement. A 3D finite difference method was employed to model the piled concrete tracks. A parametric study was carried out to assess the effect of varying soil condition and pile arrangements. From the analysis results, it is verified that the effect of the pile installation is significant to effectively reduce the settlement of concrete track. Optimal number of pile rows and pile spacings was proposed for the economical design of a piled concrete track. The bearing mechanism of piles was also investigated by analyzing load sharing characteristics of pile according to soil conditions and pile arrangements.

• The Journal of the Korea Contents Association
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• v.13 no.8
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• pp.482-489
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• 2013

The purpose of this study was to identify the relationship of instructional design, perceived learning transfer, and satisfaction. The data were collected using questionnaire from the sample of 239 nursing students. The level of learning transfer was explained by introduction with learning context & providing guidance and initial attention. The level of learning transfer was explained by learning object with motivation, learning goal alignment, accessibility and feedback & adaptation. The level of program satisfaction was explained by introduction with learning context & providing guidance and initial attention. The level of program satisfaction was explained by learning object with motivation, presentation design, interaction availability, feedback & adaptation, learning goal alignment and contents quality. The findings serve as basic data to design e-Learning program to improve learning transfer and satisfaction.

• Proceedings of the Korea Technology Innovation Society Conference
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• 2017.05a
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• pp.873-900
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• 2017

본 연구는 사회연결망 분석이론을 통해 원자력 과학기술에 대한 사회과학 연구의 경향적 특징을 파악하고, 동 분야의 주요 연구주제와 하부 연구분야를 도출하기 위해 수행되었다. 연구대상은 1957년부터 2016년까지 국내 학술지에 게재된 원자력 관련 사회과학 분야 연구논문 605건으로, 저자가 제시한 키워드 간 관계망 형성을 통해 네트워크 분석을 수행하였다. 분석결과, 첫째 국내에서 수행된 원자력 관련 사회과학 연구의 기술통계적 특징을 확인하였다. 원자력 사회과학 연구는 1957년부터 시작되어 꾸준히 수행되어졌는데, 2011년을 기점으로 논문발표가 급격히 증가했다. 주로 법학, 행정학, 정책학, 정치학의 연구가 대학 내 연구자를 중심으로 수행되어 왔다. 원자력 관련 기술개발이 주로 정부 출연연구기관에서 수행된다는 점을 고려 했을 때, 향후 사회과학 분야에 있어 대학과 출연기관 간의 역할분담이 필요하다. 둘째, 후쿠시마 원전사고가 발생한 2011년을 기점으로 사회과학의 원자력에 관한 연구가 양적, 질적으로 본격적으로 활성화 되었다. 원자력 관련 사회과학 지식 네트워크는 2011년 이전에 비해 규모면에서 큰 차이를 보였다. 또한, 네트워크 중심성 분석결과, 후쿠시마 사고 이전 사회과학 연구자들의 연구경향은 핵비확산, 과학기술 정책, 사회수용성이었다면, 후쿠시마 이후에는 원전해체, 손해배상, 에너지믹스, 탈핵운동 등과 같은 다양한 원자력 현안으로 확대되었다. 셋째, 하부 연구분야 도출을 통해 특정 연구주제별 쏠림현상을 확인했다. 하부 네트워크 분석 결과, 제시된 9개의 하부 연구분야는 네트워크 속성 값에서 차이를 보였다. 특히, 법학 관련 연구주제가 가장 높은 밀도를 갖는 반면 지속가능 발전과 에너지 믹스 관련 연구주제의 밀도가 가장 낮게 나타났다. 본 연구는 원자력에 관련된 학자의 인식을 연구경향 분석을 통해 파악한다는 점에서 의의가 있으며, 이는 추후 원자력 관련 정책연구자 혹은 정책결정자에게 유용한 기초자료를 제공할 것이라 기대된다.

• Current Research on Agriculture and Life Sciences
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• v.31 no.4
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• pp.256-264
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• 2013

This study presents a greening plan for the under space of elevated rail tracks to reducing landscape impairment and improve the streetscape. This study focuses on a section of the Daegu Metro line number 3 that includes a concentration of high-rise apartments and commercial areas. First, different types of planting were categorized for the under space of the elevated rail track, and then images of each planting type were created using a 3D simulation tool to evaluate the visual characteristics. The landscape images and related adjectives were assessed using a survey. As a result, rows of flower trees received the highest evaluation, and 'harmony' was identified as the most important factor affecting the railscape preference. These results can be important data for establishing an efficient greening plan for the under space of elevated rail tracks.

• Journal of Navigation and Port Research
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• v.36 no.3
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• pp.175-180
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• 2012

The shape of floating superstructure is the same as other buildings, but the foundation is based not on land but on a floating body. Unlike inland structures, they are largely influenced by the wave load. Deformation of the floating pontoon due to the wave loads affects the connection, which in turn causes problems related to the habitability and safety to the superstructure users. Accordingly, this study conducted elastic analysis regarding rigid connection and semi-rigid connection by the integration analysis that combined together the superstructure and pontoon of the 3-D floating structure. Moreover, this study investigated the results of the separation analysis excluding pontoon and the integration analysis. In addition, elasticity analysis was used to divide up the wave loads cases, and to classify the moment and displacement of the structure depending on connection following the changes in the wave loads.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.47 no.1
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• pp.66-74
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• 2019

Instead of securing thermophysical properties throughout the entire lunar surface, a theoretical method to predict the lunar surface temperature accurately using improved Lumped System Model (LSM) was developed. Based on the recently published research, thermal mass per unit area at the top regolith layer is assumed uniform. The function of bottom conductive heat flux was introduced under the theoretical background. The LSM temperature prediction agrees well with the DLRE measurement except for dusk, dawn and high latitude region where the solar irradiation is weak. The relative large temperature discrepancy in such region is caused by the limit of the bottom conductive heat flux model. The surface temperature map of the moon generated by the LSM method is similar to the DLRE measurement except for the anomalous temperature zones where surface topography and thermophysical properties appear in highly uneven.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.30 no.2C
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• pp.95-107
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• 2010

To calculate the end bearing capacity of a drilled Shaft socketed into the rockmass, the unconfined compression strength could be used. But it is difficult to find the unconfined compression strength because it is impossible to get undisturbed samples in weathered soils and rocks. So, to calculate the end bearing capacity, the existing bearing formula could not be used. In this study, for five zones (near pile tip, tip~lower 1D, tip~lower 2D, upper 1D~lower 1D, upper 1D~lower 2D), the relationships between the characteristic values of in-situ tests(SPT, DCPT PMT, BST) and the end bearing capacity of drilled shafts were analysed. As a result, DCPT results were represented the best credibility. Also, a design chart of end bearing capacity using DCPT was suggested.

• Journal of the Earthquake Engineering Society of Korea
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• v.4 no.1
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• pp.63-76
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• 2000

구조물-지반 상호작용에서 알려진 것처럼 구조물 지진응답은 구조물하부 지반조거에 따라 영향을 받는데 UBC-97을 포함한 여러내진설계규준에서 지반사태 영향을 반영하고 있다 이 연구에서는 기초크기 기초밑 지반깊이, 입력지진 작용점 및 기초 근입깊이 등의 영향을 살펴보고 깊은 지반 위에 세워진 구조물의 평균응답스펙트럼을 UBC-97 탄성응답스펙트럼과 비교하기 위해 구조물-지반 상호작용을 고려한 지진해석을 가상 3차원 유한요소법과 부구조물법을 이용하여 1952년 Taft와 1940년 El Centro 지진기록을 주파수영역에서 수행하였다 연구결과에 의하면 기초크기는 구조물 응답에 별 영향이 없고 기초저면 지반깊이는 구조물체계의 고유주기와 최대가속도를 변경시켰다 또 입력지진의 합리적 작용점은 기초저면이라는 것이 확인되었으며 깊은 지반위에 놓인 기초의 근입은 저주기영역에서 구조물 응답을 상당히 줄어들게 하였다 한편 30m 깊은 지반위에 세워진 구조물의 평균가속도와 UBC-97 가속도를 비교한 결과 UBC-97 탄성응답스펙트럼에 의한 구조물 내진설계가 안전하지 못할 수도 있으므로 UBC-97 지진계수의 할증이 필요하다.