• Structural Engineering and Mechanics
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• 제64권4호
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• pp.437-447
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• 2017

Explicit expressions for rapid prediction of inelastic design quantities (considering cracking of concrete) from corresponding elastic quantities, are presented for multi-storey composite frames (with steel columns and steel-concrete composite beams) subjected to service load. These expressions have been developed from weights and biases of the trained neural networks considering concrete stress, relative stiffness of beams and columns including effects of cracking in the floors below and above. Large amount of data sets required for training of neural networks have been generated using an analytical-numerical procedure developed by the authors. The neural networks have been developed for moments and deflections, for first floor, intermediate floors (second floor to ante-penultimate floor), penultimate floor and topmost floor. In the case of moments, expressions have been proposed for exterior end of exterior beam, interior end of exterior beam and both interior ends of interior beams, for each type of floor with a total of twelve expressions. Similarly, in the case of deflections, expressions have been proposed for exterior beam and interior beam of each type of floor with a total of eight expressions. The proposed expressions have been verified by comparison of the results with those obtained from the analytical-numerical procedure. This methodology helps to obtain the inelastic design quantities from the elastic quantities with simple calculations and thus would be very useful in preliminary design.

• 한국강구조학회 논문집
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• 제19권1호
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• pp.87-98
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• 2007

일반적으로 가교량은 주형와 강재교각이 강결 연결된 강재 라멘구조를 형성하고 있다. 강재 라멘구조의 경우, 작용하는 하중에 의해 축력 및 휨을 받는 부재/축력 및 휨을 동시에 받는 부재가 발생한다. 본 연구에서는 이러한 부재에 대해서 시스템 좌굴해석을 통하여 가교량 주요부재의 유효길이를 산정하고 이를 이용하여 안정성 해석을 수행한다. 이를 위하여 실제 설계/시공될 수 있는 가교의 6가지 유형을 선택하고, 고정하중, 온도하중 그리고, 활하중조합에 대한 3차원 좌굴설계를 실시한다. 결과적으로 6가지 가교에 대한 사례연구를 통하여 주형 및 교각부의 유효길이 산정법, 3차원 좌굴모드에 대한 고찰, 그리고 2차해석의 효용을 조사한다.

• 항공우주시스템공학회지
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• 제13권5호
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• pp.57-64
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• 2019

항공전자 시스템은 유지비용 감소 및 운용성능 향상을 위하여 기능을 모듈화, 통합화 설계를 적용한 모듈 통합형 항공 전자 시스템으로 개발 되어지고 있으며, 다양한 임무 제어 수행을 위해서 가상화 기술을 적용한 파티셔닝 운용체제를 적용 하고 있다. 가상화 기술을 적용 할 경우 CPU 처리 부하 분배는 중요한 고려 대상이며, 특히 입출력 처리 시간에 대한 불확실성은 안정성 있는 항공전자 시스템 설계에 있어 위험 요소 중 하나이다. 본 논문에서는 유즈케이스를 통해 입/출력 처리 방식에 따르는 CPU 처리 부하량을 비교 분석하여 공간적/시간적 파티셔닝 예시에 적용함으로써 입/출력 처리 방식의 영향성을 검토하고자 한다.

• 한국안전학회지
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• 제35권3호
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• pp.6-15
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• 2020

This study examined the structural behaviors and ultimate loads of assembled system scaffolds by load tests. Considering the number of bay and bracing installation, four specimens were tested. The bays were divided into 1 bay and 2 bays, with and without the bracing member installed. Failure modes and horizontal displacements show that the whole column buckled without showing no point of inflection in the column, regardless of whether or not braces were installed. Thus, the current design method of selecting the vertical spacing between the horizontal members of the system scaffold as the effective buckling length underestimates the effective buckling length. In case of 1 bay specimens, the ultimate loads between specimens with and with bracing members are similar. However, in case of 2 bay specimens, the specimen with bracing members shows the increased ultimate load of 36% compared with that without bracing members. In addition, as the number of bays in the system scaffold increases, the ultimate load of the unit vertical column increases in case of the specimen with bracing installation. However, in the specimen without bracing members, the ultimate load of the unit column reduces with the increment of the number of bays due to the torsional buckling. Therefore, it is essential to install bracing members to increase the whole strength of system scaffolds and the ultimate load of the unit column.

• 터널과지하공간
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• 제29권3호
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• pp.135-147
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• 2019

본 논문은 기계시스템의 하중추정 기법 및 적용사례 소개가 목적이다. 이를 위해 진동기반 하중추정 기법의 이론적 배경 및 하중정량화 절차를 구체적으로 설명하였다. 또한 충격하중 및 진동이 발생하는 천공장비에 적용하여 진동기반 하중추정 기법의 적용성과 한계점을 분석하고 이에 대한 대응책에 대해 논의하였다. 마지막으로, 하중추정 기술의 추가 연구의 필요성을 토의하고, 새로운 충격하중 측정기술 개발을 위한 방법론을 제안하였다.

• 대한토목학회논문집
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• 제42권3호
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• pp.299-309
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• 2022

신뢰도기반 교량설계기준에서 적용할 수 있는 새로운 종류의 차량활하중계수를 제시한다. 현재 사용하고 있는 차량활하중계수 1.8에 대한 적절성을 차량활하중의 재현주기와 교량설계수명에 기초하여 분석하였다. 중력방향하중 지배 한계상태에 대한 목표신뢰도지수 3.72는 적절한 논거 없이 너무 높게 설정된 값이며, 이에 상응하는 하중계수 1.8은 100년 설계수명 교량에서 재현주기 약 670만년 정도에 해당하는 활하중 파괴점을 나타내는 무의미한 값이라는 것을 보였다. 설계 풍속이나 지반가속도와 동일한 재현주기를 차량활하중에도 적용하면 차량활하중계수는 1.15 정도가 되고 목표신뢰도지수는 한계상태를 지배하는 하중에 따라서 2.0 혹은 2.5에 해당하게 된다. 제안한 목표신뢰도지수에 대한 전체 하중-저항계수 조합은 최적화에 의하여 산정하였다.

• 전자공학회논문지S
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• 제34S권5호
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• pp.94-103
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• 1997

It is necesary that analog buffer circuit should drive an external load in the VLSI design such as switched capacitor efilter (SCF), D/A converter, A/d converter, telecommunicatin circuit, etc. The conventional CMOS buffer circuit have many probvlems according as CMOS technique. Firstly, Capacity of large load ar enot able to opeate well. The problem can be solve to use class AB stages. But large load are operated a difficult, because an element of existing CMOS has a quadratic functional relation with inptu and outut voltage versus output current. Secondly, whole circuit of dynamic rang edecrease, because a range of inpt and output voltages go down according as increasing of intergration rate drop supply voltage. In this paper suggests that new differential CMOS line driver make out of operating an external of large load. In telecommunication's chip case transmission line could be a load. It is necessary that a load operate line driver. The proposal circuit is planned to hav ea high generation power rnage of voltage with preservin linearity. And circuit of capability is inspected through simulation program (HSPICE).

• 대한물리치료과학회지
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• 제31권1호
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• pp.46-52
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• 2024

Background: This study aims to investigate compensatory strategy in a dog with glenoid dysplasia using kinetic gait analysis before and after reconstruction of medial patellar luxation. Design: Case report Method: On the platform, gait analysis was evaluated for a dog with congenital luxation and bilateral medial patellar luxation (MPL). A dog was evaluated for maximal vertical force (MVF), body load distribution (BLD), and symmetry index (SI), including the left forelimb with congenital luxation before MPL surgery, 15 days of surgery, and 40 days of surgery. Result:: In the comparison between the preoperative and the 15 days of surgery, the MVF of the bilateral forelimbs, especially in the non-affected forelimbs, increased, and the SI also increased. For BLD, the maximum load distribution increased, but the total load distribution decreased. In the comparison of 15 days and 40 days of surgery, MVF and BLD increased, and SI decreased on 40days of surgery. Conclusions: In a dog, the shift in weight load to the non-affected side occurs all the limbs, affecting the peak vertical force, weight load distribution, and symmetry index.

• 한국방재학회:학술대회논문집
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• 한국방재학회 2008년도 정기총회 및 학술발표대회
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• pp.485-488
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• 2008

The structure supporting road sign is a road information facility for ensuring the safe transportation and smooth traffic. But, lots of road information facilities were damaged by the typhoon "Maemi" in 2003. Such damaged facilities should be rehabilitated and could increase economic loss by causing traffic accident. Therefore, in this study, behavior that reduce wind load and improve wind resistance of the structure supporting road sign are studied about wind load beyond design specification by abnormal climate as below. The first is wind load reducing technique such that shear key resist wind load that is not greater than design wind speed but in case that it is over the design wind limit, column member is rotated on the inner steel pipe axis by the brittle failure of shear key. The second is the technique such that fail-safe the overturning of road sign panel by equipment installation in the vertical member. The third is the technique of installing stiffening plate inside the vertical member to relieve stress concentration.

• 국제학술발표논문집
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• The 6th International Conference on Construction Engineering and Project Management
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• pp.730-731
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• 2015

This study aims at giving the framework to estimate the environmental load at planning and schematic phase. With increasing awareness of environmental issues, the effort to reduce the environmental impacts caused by human activity has been increasingly enlarged. So far most of researches estimating CO₂ emissions have analyzed energy consumption based on BOQ (Bills of Quantity) acquired after detailed design. There is also lack of reliability in the estimated environmental impact using the basic unit of a facility at the planning stage, because it uses a limited specific section of historical data. Thus, this study is targeted at developing framework to assess reliable environmental loads based on information available at project early phases by making case-bases from historical design information on PSC Beam Bridge. Historical database is built on the basis of the LCA (Life Cycle Assessment) and in order to set input information for estimating model, the literature about information in an early project phase are reviewed. Using the information available in the planning and schematic design stage, the Framework is presented to estimate the environmental load in an early stage in the project. Developing an environmental load estimation model in accordance with the Framework presented in this study, it is expected that the environmental load in the initial project phase can be estimated more quickly and accurately.