• 한국강구조학회 논문집
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• 제25권1호
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• pp.15-24
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• 2013

본 논문은 반복하중을 받는 CFT 합성골조의 더블 웨브앵글 접합부의 휨모멘트 내력에 대해 체계적으로 수행된 유한요소 연구로부터 얻은 결과를 제시하고 있다. 합성 부분강접 CFT 접합부의 회전강성, 휨모멘트 내력 및 파괴모드를 연구하기 위하여 3차원 비선형 유한요소 해석이 수행되었다. 부가적인 다양한 구조적 거동은 앵글의 두께 및 고강도 강봉 게이지 거리로 더블 웨브앵글 접합부의 파라미터에 대한 영향을 설명하고 있다. 해석모델의 적합성은 정적 유한요소해석 결과로부터 얻은 모멘트-회전각 곡선을 Richard의 회귀분석을 통하여 비교 분석하였다.

• Smart Structures and Systems
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• 제9권3호
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• pp.287-301
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• 2012

It is well known that overloaded vehicles may cause severe damages to bridges, and how to estimate and evaluate the status of the overloaded vehicles passing through bridges become a challenging problem. Therefore, based on the monitored strain data from a structural health monitoring system (SHM) installed on a bridge, a method is recommended to identify and analyze the probability of overloaded vehicles. Overloaded vehicle loads can cause abnormity in the monitored strains, though the abnormal strains may be small in a concrete continuous rigid frame bridge. Firstly, the abnormal strains are identified from the abundant strains in time sequence by taking the advantage of wavelet transform in abnormal signal identification; secondly, the abnormal strains induced by heavy vehicles are picked up by the comparison between the identified abnormal strains and the strain threshold gotten by finite element analysis of the normal heavy vehicle; finally, according to the determined abnormal strains induced by overloaded vehicles, the statistics of the overloaded vehicles passing through the bridge are summarized and the whole probability of the overloaded vehicles is analyzed. The research shows the feasibility of using the monitored strains from a long-term SHM to identify the information of overloaded vehicles passing through a bridge, which can help the traffic department to master the heavy truck information and do the damage analysis of bridges further.

• 한국지반신소재학회논문집
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• 제3권2호
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• pp.3-11
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• 2004

침식방지형 섬유대공은 호안 또는 하천의 하천침식과 포락 방지를 위한 토목공사용 섬유자재로 내부에 유동성 콘크리트 또는 모르타르 등을 고압의 콘크리트 펌프로 주입하여 콘크리트 블록을 형성되도록 하는 제방 보호용 토목섬유공법이다. 그러나 기존에 개발된 침식방지형 섬유대공은 다량의 콘크리트 그라우팅제 사용에 따른 경제성 및 친환경성 측면에서 문제점을 가지고 있으며, 섬유대공의 안정성이 섬유대/비탈면 원지반의 마찰특성에 의존하도록 되어 있어 급경사 비탈면 적용에 한계가 있다. 본 연구에서는 다량의 콘크리트를 사용하는 기존 섬유대호안공의 경제성 및 친환경성을 개선하고자 역학적인 방틀형태를 시공이 간편한 섬유대를 이용하여 구축하고, 구조적 안정성 및 비탈면 전면부의 식생 및 사석 호안시스템 지지 등을 앵커로 처리하는 경제적이면서도, 안정적인 섬유대공을 개발하여 실내모형시험에 의한 침식저항성평가 및 현장 적용성 평가 등을 수행하였다.

• 한국실내디자인학회논문집
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• 제23권6호
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• pp.169-177
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• 2014

The purpose of this study is to analyze the design characteristics of Hanok hotel. This study was approached by using theoretical investigation and a field survey. The field survey analyzed the current situations by conducting the master plan layout, architecture and interior design of the Hanok hotel. The field survey was tested by examining four different Hanok hotels from February 2014 to July 2014. After all, the results were analyzed based on given categories. The results of this research can be summarized as following. First, the characteristic of the master plan layout in Hanok hotel was appeared as "ㄷ" and "ㅡ" shapes. Those layouts were based on the spatial and the functional aspects of Hanok hotel facilities. Second, three different structural methods such as the korean traditional wooden structure, concrete, and masonry method were used in Hanok hotel construction to deliver the traditional architecture aspects while considering the functionality and convenience of the building. Third, most of Hanok hotels had the limited furniture range. The consideration of using several types of traditional furniture in different rates of the guest rooms help to increase the service quality and customer's satisfaction. Fourth, there were no diversity of using materials and colors in Hanok hotels that only few of them were used to express the traditional look. Fifth, the local characteristics were found in several Hanok hotels. To reflect the local characteristics in Hanok hotel is to construct a suitable environment to fit in nature and also it is easily to convey the local culture to others.

• Earthquakes and Structures
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• 제5권6호
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• pp.703-731
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• 2013

In order to verify the applicability of buckling restrained braces (BRB's) and fiber reinforced polymer (FRP) sheets to the seismic strengthening of a low-rise RC building having the irregularities of a soft/weak story and torsion at the ground story, a series of earthquake simulation tests were conducted on a 1:5 scale RC building model before, and after, the strengthening, and these test results are compared and analyzed, to check the effectiveness of the strengthening. Based on the investigations, the following conclusions are made: (1) The BRB's revealed significant slips at the joint with the existing RC beam, up-lifts of columns from RC foundations and displacements due to the flexibility of foundations, and final failure due to the buckling and fracture of base joint angles. The lateral stiffness appeared to be, thereby, as low as one seventh of the intended value, which led to a large yield displacement and, therefore, the BRB's could not dissipate seismic input energy as desired within the range of anticipated displacements. (2) Although the strengthened model did not behave as desired, great enhancement in earthquake resistance was achieved through an approximate 50% increase in the lateral resistance of the wall, due to the axial constraint by the peripheral BRB frames. Finally, (3) whereas in the original model, base torsion was resisted by both the inner core walls and the peripheral frames, the strengthened model resisted most of the base torsion with the peripheral frames, after yielding of the inner core walls, and represented dual values of torsion stiffness, depending on the yielding of core walls.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 1991년도 추계학술발표회 논문집 지반공학에서의 컴퓨터 활용 COMPUTER UTILIZATION IN GEOTECHNICAL ENGINEERING
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• pp.108-122
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• 1991

주어진 터널 斷面 및 地盤條件을 對象으로 1次元 有限要素 프로그램인 MrSoil을 利用하여 數値解析을 遂行하고 그 結果를 本稿에 收錄하였다. 解析 모델은 過去의 터널 計測 結果等에 根據하여 터널 掘進 影 이 充分히 적은 地域까지로 擴張 設定하여 境界條件에 의한 解析結果에의 影響을 最小化하도록 하였으며, 3次元的인 터널 擧動을 適切히 Simulation 하기 위하여 施工順序를 導入하여 段階別로 解析을 遂行하였다. 解析結果 터널 天井部는 最大 約 35mm의 沈下가 豫想되며, 地表面 沈下는 13mm 以內로서 地上 構造物의 構造的인 被害는 없을 것으로 判斷된다. 支保工인 Shotcrete와 Rockbolt의 最大應力 및 軸力도 各各 84 Kg/cm2 및 9론 以內로서 許容値 以內이고, 掘面 周邊의 塑性領域은 Rockbolt 길이 以內로 制限되고 있으므로 天井部에 Forepoling을 設置한다면, 터널 安全에는 影響을 미치지 않을 것으로 判斷되므로 本 터널은 合理的이며 適切히 設計된 것으로 評價된다.

• Steel and Composite Structures
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• 제20권4호
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• pp.731-748
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• 2016

Pile-to-pilecap connection performance is important as Integral abutment bridges (IABs) have no expansion joints and their flexible weak-axis oriented supporting piles take the role of the expansion joint. This connection may govern the bridge strength and the performance against various lateral loads. The intention of this study is to identify crack propagation patterns when the pile-to-pilecap connection is subjected to lateral loadings and to propose novel connections for improved performance under lateral loadings. In this study, eight different types of connections were developed and modeled, using Abaqus 6.12 to evaluate performances. Three types were developed by strengthening the connections using rebar or steel tube: (i) PennDOT specification; (ii) Spiral rebar; and (iii) HSS tube. Other types were developed by softening the connections using shape modifications: (i) cylindrical hole; (ii) reduced flange; (iii) removed flange; (iv) extended hole; and (v) slot hole connection types. The connections using the PennDOT specification, HSS tube, and cylindrical hole were shown to be ineffective in the prevention of cracks, resulting in lower structural capacities under the lateral load compared to other types. The other developed connections successfully delayed or arrested the concrete crack initiations and propagations. Among the successful connection types, the spiral rebar connection allowed a relatively larger reaction force, which can damage the superstructure of the IABs. Other softened connections performed better in terms of minimized reaction forces and crack prevention.

• Structural Engineering and Mechanics
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• 제63권6호
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• pp.713-723
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• 2017

As a new type of ballastless track, longitudinal continuous slab track (CST) has been widely used in China. It can partly isolate the interaction between the ballastless track and the bridge and thus the rail expansion device would be unnecessary. Compared with the traditional track, CST is composed of multi layers of continuous structures and various connecting components. In order to investigate the performance of CST on a long-span bridge, the spatial finite element model considering each layer of the CST structure, connecting components, bridge, and subgrade is established and verified according to the theory of beam-rail interaction. The nonlinear resistance of materials between multilayer track structures is measured by experiments, while the temperature gradients of the bridge and CST are based on the long-term measured data. This study compares the force distribution rules of ballasted track and CST as respectively applied to a long span bridge. The effects of different damage conditions on CST structures are also discussed. The results show that the additional rail stress is small and the CST structure has a high safety factor under the measured temperature load. The rail expansion device can be cancelled when CST is adopted on the long span bridge. Beam end rotation caused by temperature gradient and vertical load will have a significant effect on the rail stress of CST. The additional flexure stress should be considered with the additional expansion stress simultaneously when the rail stress of CST requires to be checked. Both the maximum sliding friction coefficient of sliding layer and cracking condition of concrete plate should be considered to decide the arrangement of connecting components and the ultimate expansion span of the bridge when adopting CST.

• 한국건설순환자원학회논문집
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• 제2권4호
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• pp.307-313
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• 2014

부식촉진시험의 가장 확실하고 신뢰성이 높은 방법은 해양폭로 시험장에 직접 폭로시켜 철근부식모니터링을 실시하는 방법이지만 장기간이 소요되는 단점이 있다. 그래서 이를 대체하는 수단으로 많은 연구들이 진행되어 왔다. 하지만 부식촉진시험이 폭로환경의 어느 정도 기간에 상응하느냐는 상관성에 대한 규정은 정해져 있지 않은 상황이다. 본 논문에서는 간만대, 침지내 환경을 재현한 철근부식촉진시험과 장기폭로시험을 실시하였다. 환경조건을 변수로 시험을 실시하였으며, 반전지전위법을 통한 철근부식 모니터링을 실시하였다. 부식촉진 시험결과 시험조건 별 상대부식개시시점 도출을 할 수 있었으며, 내구성 해석 프로그램인 Life365와 염화물적정시험을 통해 염화물침투해석을 실시하였다.

• 한국IT서비스학회지
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• 제17권3호
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• pp.117-138
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• 2018

The purpose of this study is to empirically analyze the relationships between the Boundary Spanning Activities (BSA) of project team and system performance in ERP system development projects. We could theoretically classify the BSA in the ERP development projects into five categories on the basis of existing studies on the BSA in the research fields of organization theory, new product development, and information systems development. These five categories are 'Ambassador' activities, 'Task-coordinator' activities, 'Scout' activities, 'Sentry' activities and 'Guard' activities. And the relationship between the implementation level of activities included in each category and the project performance (system usage and users' satisfaction) was hypothesized with respect to five BSA categories. In order to test the hypotheses, we conducted on/offline survey of the participants who were involved in the ERP system development projects, and received 345 valid responses. The unit of analysis was the project team, and the total number of teams that survey participants belonged to were 103 ones. The Structural Equation Model Analysis using the SMART PLS 3.0 was applied to statistically testing the hypotheses. The results showed that 10 hypotheses among 12 hypotheses could be supported. The theoretical implications of this study can be summarized as following; first, redefining and categorizing the BSA (Boundary Spanning Activities) in the ERP system development projects, secondly, deriving measurement indicators of the implementation level for each BSA category and statistically proving the validity and the reliability of them, and finally, suggesting the theoretical background of expanding the management area of ERP systems development projects. Furthermore, the practical implication of this study is that concrete BSA items which are empirically derived can be utilized as effective guidelines for successfully implementing the BSA in the process of managing the ERP system development projects.