• Title/Summary/Keyword: global frame

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Optimization of Frame Structures with Natural Frequency Constraints (고유진동수 제약조건을 고려한 프레임 구조물의 최적화)

  • Kim, Bong-Ik;Lee, Seong-Dae
    • Journal of Ocean Engineering and Technology
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    • v.24 no.6
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    • pp.109-113
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    • 2010
  • We present the minimum weight optimum design of cross sectional for frame structures subject to natural frequency. The optimum design in this paper employ discrete and continuous design variables and Genetic Algorithms. In this paper, Genetic Algorithms is used in optimization process, and be used the method of Elitism and penalty parameters in order to improved fitness in the reproduction process. For 1-Bay 2-Story frame structure, in examples, continuous and discrete design variables are used, and W-section (No.1~No.64), from AISC, discrete data are used in discrete optimization. In this case, Exhaustive search are used for finding global optimum. Continuous variables are used for 1-Bay 7-Story frame structure. Two typical frame structure optimization examples are employed to demonstrate the availability of Genetic Algorithms for solving minimum weight optimum of frame structures with fundamental and multi frequency.

Modified Stiffness Matrix of Frame Reflecting the Effect of Local Cracks (국부적 균열의 영향을 고려한 수정된 프레임 강성행렬)

  • 이상호;송정훈;임경훈
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 2002.04a
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    • pp.353-360
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    • 2002
  • The objective of this study is to develop a technique that analyzes the global behavior of frame structures with local cracks. The technique is based on frame analysis and uses the stiffness matrix of cracked frame element. An algorithm proposed here analyzes a frame structure with local transverseedge cracks, considering the effects of crack length and location. Stress intensity factors are employed to calculate additional local compliance due to the cracks based on linear elastic fracture mechanics theory, and then this local compliance is utilized to derive the stiffness matrix of the cracked frame element. In order to verify the accuracy and reliability of the proposed approach, numerical results are compared with those of Finite Element Method for the cracked frame element, and the effects of single crack on the behavior of truss structure are also examined.

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A Method QSR(Qualitative Spatial Representation and Reasoning)-14 Using a Global Reference Frame for a Dynamic Physical World (동적 물질세계를 위해 전역적 참조 프레임을 사용한 정성적 공간 표현 및 추론법 QSR-14)

  • Park, Gyu-Dong;Byun, Young-Tae
    • Korean Journal of Cognitive Science
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    • v.22 no.1
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    • pp.19-38
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    • 2011
  • When quantitative representation and reasoning about space is difficult or impossible in a real world, we can use qualitative representation and reasoning. RCC-8 is a well-known qualitative method for 2D space. RCC-8, in which a basic ontological primitive entity for space is a region, shows the connection-based logics and the conceptual neighbors and transitions of topological status between two regions. The transitions happen by changing position or size of regions. However, more aspects have to be considered for representing and reasoning of the world. We propose a modified and extended method QSR-14 for qualitative spatial representation and reasoning of a dynamic physical 2D world in the gravitation field. We mention the need of a global reference frame and describe QSR-14 in detail for representing and reasoning of physical and chemical changes of a real world using the global reference frame. We believe QSR-14 is appropriate for the qualitative spatial representation and reasoning of a dynamic physical world. The usefulness of QSR-14 is shown with several examples.

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Experimental and analytical evaluation of a low-cost seismic retrofitting method for masonry-infilled non-ductile RC frames

  • Srechai, Jarun;Leelataviwat, Sutat;Wongkaew, Arnon;Lukkunaprasit, Panitan
    • Earthquakes and Structures
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    • v.12 no.6
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    • pp.699-712
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    • 2017
  • This study evaluates the effectiveness of a newly developed retrofitting scheme for masonry-infilled non-ductile RC frames experimentally and by numerical simulation. The technique focuses on modifying the load path and yield mechanism of the infilled frame to enhance the ductility. A vertical gap between the column and the infill panel was strategically introduced so that no shear force is directly transferred to the column. Steel brackets and small vertical steel members were then provided to transfer the interactive forces between the RC frame and the masonry panel. Wire meshes and high-strength mortar were provided in areas with high stress concentration and in the panel to further reduce damage. Cyclic load tests on a large-scale specimen of a single-bay, single-story, masonry-infilled RC frame were carried out. Based on those tests, the retrofitting scheme provided significant improvement, especially in terms of ductility enhancement. All retrofitted specimens clearly exhibited much better performances than those stipulated in building standards for masonry-infilled structures. A macro-scale computer model based on a diagonal-strut concept was also developed for predicting the global behavior of the retrofitted masonry-infilled frames. This proposed model was effectively used to evaluate the global responses of the test specimens with acceptable accuracy, especially in terms of strength, stiffness and damage condition.

Limit states of RC structures with first floor irregularities

  • Favvata, Maria J.;Naoum, Maria C.;Karayannis, Chris G.
    • Structural Engineering and Mechanics
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    • v.47 no.6
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    • pp.791-818
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    • 2013
  • The seismic performance of reinforced concrete (RC) frame structures with irregularities leading to soft first floor is studied using capacity assessment procedures. The soft first story effect is investigated for the cases: (i) slab-column connections without beams at the first floor, (ii) tall first story height and (iii) pilotis type building (open ground story). The effects of the first floor irregularity on the RC frame structure performance stages at global and local level (limit states) are investigated. Assessment based on the Capacity Spectrum Method (ATC-40) and on the Coefficient Method (FEMA 356) is also examined. Results in terms of failure modes, capacity curves, interstory drifts, ductility requirements and infills behaviour are presented. From the results it can be deduced that the global capacity of the structures is decreased due to the considered first floor morphology irregularities in comparison to the capacities of the regular structure. An increase of the demands for interstory drift is observed at the first floor level due to the considered irregularities while the open ground floor structure (pilotis type) led to even higher values of interstory drift demands at the first story. In the cases of tall first story and slab-column connections without beams soft-story mechanisms have also been observed at the first floor. Rotational criteria (EC8-part3) showed that the structure with slab-column connections without beams exhibited the most critical response.

A Study on Stability Hanging Guide Frame used in Floating Crane (해상 Crane용 Guide Frame의 안정성에 관한 연구)

  • 장동일;민인기
    • Journal of the Korean Society of Safety
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    • v.14 no.1
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    • pp.33-40
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    • 1999
  • In this paper, a damaged example of hanging guide frame used in the lifting of shore protection caisson was investigated. An examination of the stress and stability of members was carried out by structural analysis and the causes of damages was investigated. The stability analysis considering local and global stress buckling was performed. As a result of stability analysis. the first structure was unstable structure. Therefore improved structure was examined and the best effective methodology was the reassignment of wire.

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The Moderating Effect of Gain and Loss Framework between Advertisement Uniqueness and Brand Attachment

  • Park, Seungbae;Hong, Jaewon
    • Journal of the Korea Society of Computer and Information
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    • v.24 no.1
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    • pp.231-238
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    • 2019
  • The objective of this study is to understand the relationship between type of advertising and brand attachment. We divide advertising frame into loss and gain frame and examine the effect on brand attachment, The effect of unique advertising on brand attachment and the effects of interaction effects on brand attachment were examined. The results showed that the effect of the loss and gain frame on brand attachment was statistically significant. It also showed that unique advertising had positive effect on brand attachment. Moreover, the interaction effects of the advertising frame and the uniqueness of advertising have been shown to affect brand attachment. That is, the more emphasis on gain in advertising frame and the more unique advertising, the more effective on brand attachment.

Camera Motion Estimation using Geometrically Symmetric Points in Subsequent Video Frames (인접 영상 프레임에서 기하학적 대칭점을 이용한 카메라 움직임 추정)

  • Jeon, Dae-Seong;Mun, Seong-Heon;Park, Jun-Ho;Yun, Yeong-U
    • Journal of the Institute of Electronics Engineers of Korea CI
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    • v.39 no.2
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    • pp.35-44
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    • 2002
  • The translation and the rotation of camera occur global motion which affects all over the frame in video sequence. With the video sequences containing global motion, it is practically impossible to extract exact video objects and to calculate genuine object motions. Therefore, high compression ratio cannot be achieved due to the large motion vectors. This problem can be solved when the global motion compensated frames are used. The existing camera motion estimation methods for global motion compensation have a large amount of computations in common. In this paper, we propose a simple global motion estimation algorithm that consists of linear equations without any repetition. The algorithm uses information .of symmetric points in the frame of the video sequence. The discriminant conditions to distinguish regions belonging to distant view from foreground in the frame are presented. Only for the distant view satisfying the discriminant conditions, the linear equations for the panning, tilting, and zooming parameters are applied. From the experimental results using the MPEG test sequences, we can confirm that the proposed algorithm estimates correct global motion parameters. Moreover the real-time capability of the proposed technique can be applicable to many MPEG-4 and MPEG-7 related areas.

Interactive Roles of Local versus Global Primed Identity and Advertisement Framing on Brand Evaluation (브랜드평가에 대한 아이덴티티의 점화와 광고프레임의 상호작용효과)

  • Choi, Nak Hwan;Liu, Cong
    • Science of Emotion and Sensibility
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    • v.16 no.1
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    • pp.11-28
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    • 2013
  • This article aims to explore the interactive roles of types of primed identity (local versus global identity) and types of ad framing on brand evaluations. The authors designed 2 experiments in which each experiment followed a $2{\times}2$ between-subject design. The empirical results showed that a gain-framed ad induced more positive emotional responses than a loss-framed ad, and the positive affective responses lead to more favorable brand evaluation. Furthermore, the results showed that there were interactive effects of primed identity and types of advertisement frame on brand evaluation. In the additional analysis, the results showed that when people with local identity were exposed to the gain-framed ad, they would engage in a higher level of integration processing than those in the control group, which in turn induced more favorable evaluation to the local brand. That is, the integration processing mode played a mediating role between the interaction (local id priming ${\times}$ ad frame) and the local brand evaluation. However, in the case of global brand evaluation, the integration processing mode did not play such a mediating role.

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A Proposal of Model Updating Method for Steel Frame Using Global/Local Responses (전역적/국부 응답을 이용한 철골조의 모델 업데이팅 기법 제안)

  • Oh, Byung-Kwan;Choi, Se-Woon;Kim, Yousok;Park, Hyo-Seon
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.28 no.4
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    • pp.401-408
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    • 2015
  • Conventional model updating methods for the structures have used global structural responses which are modal parameters obtained through vibration measurements. Although models updated by modal parameters estimate global structural responses accurately, they have difficulties to predict local responses for safety assesment of structural members. The safety of structural members in the structures has been evaluated through the stress estimation based on strain measurements. Thus, this study additionally uses measured strain responses of structural members to perform model updating besides modal parameters. In the proposed method, the objective functions are set to the differences of the global and local responses obtained from updated model and measurement and those functions are minimized by NSGA-II, one of the multi-objective optimization techniques. The strain responses predicted from updated model are used for safety assessment of the steel frame structures. The proposed method are verified by numerical and experimental studies through the impact hammer tests for a steel frame specimen.