• Coupled systems mechanics
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• 제5권1호
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• pp.41-58
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• 2016

The study deals with physical modeling of a typical building frame resting on pile raft foundation and embedded in cohesive soil mass using finite element based software ETABS. Both- the elements of superstructure and substructure (i.e., foundation) including soil is assumed to remain in elastic state at all the time. The raft is modelled as a thin plate and the pile and soils are treated as interactive springs. Both- the resistance of the piles as well as that of raft base - are incorporated into the model. Interactions between raft-soil-pile are computed. The proposed method makes it possible to solve the problems of uniformly and large non-uniformly arranged piled rafts in a time saving way using finite element based software ETABS. The effect of the various parameters of the pile raft foundation such as thickness of raft and pile diameter is evaluated on the response of superstructure. The response included the displacement at the top of the frame and bending moment in columns. The soil-structure interaction effect is found to increase displacement and increase the absolute maximum positive and negative moments. The effect of the soil- structure interaction is observed to be significant for the type of foundation and soil considered in the present study.

• 한국정보시스템학회지:정보시스템연구
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• 제28권4호
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• pp.251-270
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• 2019

Purpose Unlike advertising through the traditional media targeting unspecified number of people, the base of mobile environment using smartphone has expanded so that many companies can classify prospective customers according to their purpose, thereby enabling efficient targeted marketing with low cost. Design/methodology/approach This study has investigated how can marketing strategy be influenced by the price promotion type (immediate discount/delayed discount) and message framing (positive/negative) according to time pressure (low/high). Hypotheses are set through the consideration of prospect theory, endowment effect, framing effect, regulatory-focus theory, and time-pressure theory. Findings The results and interpretation of this study are as follows. First, it was found that the influence of the delayed discount on the purchase intention was larger than the immediate discount. Second, negative/loss frame messages have more influence on purchase intention than positive/profit frame messages. Third, when the price promotion type is delayed discount, the effect of the promotion message on the purchase intention when it presented by negative/loss frame is greater than the other cases. The implication of this study is that it can be used as a basic data for establishing a strategy to maximize the effectiveness of promotions effectively considering potential buyers of mobile commerce environment.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2001년도 추계학술대회논문집A
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• pp.489-494
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• 2001

This paper develops a finite element model for frontal crash analysis of a large-sized truck. It is composed of 220 parts, 70,041 nodes and 69,073 elements. This paper explains only major parts' models in detail such as frame, cab, floor, and bumper which affect on crash analysis a lot. In order to prevent penetration not only at a part itself but also between parts, all contact areas are defined using type-36, self-impact type. The developed model's reliability is validated by comparing simulation and crash test results. The results used for model validation are vehicle pulses at B-pillar, and frame and deformation of frame and cab. The frontal crash simulation is performed with the same conditions as crash test. And, it is performed using PAM-CRASH installed in super-computer SP2. The developed model whose reliability is verified may be used as a base to develop a finite element model for occupant behavior and injury coefficient analysis.

• 한국통신학회논문지
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• 제29권3C호
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• pp.408-418
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• 2004

본 논문에서는 동영상 부호화의 이동 보상 과정에서 다중의 참조 영상들을 적응적으로 이용하는 새로운 스케일러블(scalable) 부호화 기법을 제안한다. 제안 기법은 입력 신호의 특성을 고려하여. 확장계층 및 기저계층에서 다중의 이동 참조 영상들에 대한 최적 가중 값을 적응적으로 구한다. 이러한 기법을 이용하여. 확장계층의 부호화 효율 및 오류에 대한 강인성을 향상시킨다. 또한 복호기에서 전송 오류가 검출된 경우. 적응적으로 참조 영상을 선택함으로써 에러 파급(drift) 현상을 현저히 감소시킨다 실험 결과들로부터, 제안하는 적응적인 스케일러블 부호화 기법은 다양한 채널 에러(channel error) 환경에서, 기존의 스케일러블 H.263+부호화 기법에 비하여 PSNR 성능이 약 1.0㏈ 이상 향상됨을 확인할 수 있었다.

• 국제초고층학회논문집
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• 제6권1호
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• pp.1-9
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• 2017

The Pertamina Energy Tower (PET) and Manhattan West North Tower (MWNT) are two supertall towers recently designed and engineered by Skidmore, Owings & Merrill (SOM). The structural system for both buildings consists of an interior reinforced concrete core and a perimeter moment frame system, which is primarily structural steel. As is typical for tall towers with both concrete and steel elements, staged construction analysis was performed in order to account for the long term effects of creep and shrinkage, which result in differential shortening between the interior concrete core and steel perimeter frame. The particular design of each tower represents two extremes of behavior; PET has a robust connection between the perimeter and core in the form of three sets of outriggers, while the perimeter columns of MWNT do not reach the ground, but are transferred to the core above the base. This paper will present a comparison of the techniques used during the analysis and construction stages of the design process with the goal of understanding the differences in structural behavior of these two building systems in response to the long term effects of creep and shrinkage. This paper will also discuss the design and construction techniques implemented in order to minimize the differential shortening between the interior and exterior over the lifespan of these towers.

• Earthquakes and Structures
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• 제3권5호
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• pp.749-766
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• 2012

Structural control through integration of passive damping devices within the building structure has been increasingly implemented internationally in the last years and has proven to be a most promising strategy for earthquake safety. In the present paper an alternative configuration of an innovative energy dissipation mechanism that consists of slender tension only bracing members with closed loop and a hysteretic damper is investigated in its dynamic behavior. The implementation of the adaptable dual control system, ADCS, in frame structures enables a dual function of the component members, leading to two practically uncoupled systems, i.e., the primary frame, responsible for the normal vertical and horizontal forces and the closed bracing-damper mechanism, for the earthquake forces and the necessary energy dissipation. Three representative international earthquake motions of differing frequency contents, duration and peak ground acceleration have been considered for the numerical verification of the effectiveness and properties of the SDOF systems with the proposed ADCS-configuration. The control mechanism may result in significant energy dissipation, when the geometrical and mechanical properties, i.e., stiffness and yield force of the integrated damper, are predefined. An optimum damper ratio, DR, defined as the ratio of the stiffness to the yield force of the hysteretic damper, is proposed to be used along with the stiffness factor of the damper's- to the primary frame's stiffness, in order for the control mechanism to achieve high energy dissipation and at the same time to prevent any increase of the system's maximum base shear and relative displacements. The results are summarized in a preliminary design methodology for ADCS.

• Earthquakes and Structures
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• 제8권3호
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• pp.699-712
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• 2015

Bracing structures with off-centre bracing system is one of the new resistant systems that frequently used in the frame with pin connections. High ductility, high-energy dissipation and decrease of base shear are advantages of this bracing system. However, beside these advantages, reconstruction and hard repair of off-centre bracing system cause inappropriate performance in the earthquake. Therefore, in this paper, the goal is investigating the behavior of this type of bracing system with ductile element (circular dissipater), in order to providing replacement of damaged member without needing repair or reconstruction of the general system. To achieve this purpose, some numerical studies have been performed using ANSYS software, a frame with off-centre bracing system and optimum eccentricity (OBS-C-O) and another frame with the same identifications without ductile element (OBS) has been created. In order to investigate precisely on the optimum placement of circular elements under monotonic load again three steal frames were modeled. Furthermore, the behavior of this general system investigated for the first time, linear and nonlinear behavior of these two steel frames compared to each other, to achieve the benefit of using the circular element in an off-centre bracing system. Eventually, the analytical results revealed that the performance of steel ring at the end of off-centre braces system illustrating as a first defensive line and buckling fuse in the off-centre bracing system.

• 국제강구조저널
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• 제18권4호
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• pp.1431-1439
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• 2018

For floating buildings may fl oat on the water for a long time, they are constantly affected by various environmental loads such as wind and wave loads. In this study to find the wave effect on the floating building, five models are designed using steel moment resisting frame. It is assumed that the lower part of the floating building is a reinforced concrete pontoon, while the upper part is a three-story steel frame. To analyze floating buildings affected by wind and wave loads, hydro-dynamic and substructure analysis are performed. As input loads, this study set limits that the mean wind velocity is 35 m/s and the significant wave height is 0.5 m for the residential building. From the hydrodynamic analysis, the time-history acceleration of building is obtained and transformed into a base ground input for a substructure analysis of the superstructure of the building. Finally the mean of the maximum from 30 dynamic analysis of the floating buildings are used to be compared with the results of the same model on the ground. It was shown that the dynamic results with wind and wave loads are not always lesser than the static results which are calculated with static equivalent wind load for a building that is located on the ground.

• Structural Engineering and Mechanics
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• 제88권5호
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• pp.463-480
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• 2023

The buckling-restrained braced frames with eccentric configurations (BRBF-Es) exhibit stable cyclic behavior and possess a high energy absorption capacity. Additionally, they offer architectural advantages for incorporating openings, much like Eccentrically Braced Frames (EBFs). However, studies have indicated that significant residual drifts occur in this system when subjected to earthquakes at the Maximum Considered Earthquake (MCE) hazard level. Consequently, in order to mitigate these residual drifts, it is recommended to employ self-centering systems alongside the BRBF-E system. In our current research, we propose the utilization of the Direct Displacement-Based Seismic Design method to determine the design base shear for a hybrid system that combines BRBF with an eccentric configuration and a self-centering frame. Furthermore, we present a methodology for designing the individual components of this composite system. To assess the effectiveness of this design approach, we designed 3-, 6-, and 9-story buildings equipped with the BRBF-E-SCF system and developed finite element models. These models were subjected to two sets of ground motions representing the Maximum Considered Earthquake (MCE) and Design Basis Earthquake (DBE) seismic hazard levels. The results of our study reveal that although the combined system requires a higher amount of steel material compared to the BRBF-E system, it substantially reduces residual drift. Furthermore, the combined system demonstrates satisfactory performance in terms of story drift and ductility demand.

• Earthquakes and Structures
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• 제4권1호
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• pp.85-108
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• 2013

The research presented in this paper deals with the seismic protection of existing frame structures by means of passive energy dissipation. A displacement-based procedure to design dissipative bracings for the seismic protection of frame structures is proposed and some applications are discussed. The procedure is based on the displacement based design using the capacity spectrum method, no dynamic non linear analyses are needed. Two performance objective have been considered developing the procedure: protect the structure against structural damage or collapse and avoid non-structural damage as well as excessive base shear. The compliance is obtained dimensioning dissipative braces to limit global displacements and interstorey drifts. Reference is made to BRB braces, but the procedure can easily be extended to any typology of dissipative brace. The procedure has been validated through a comparison with nonlinear dynamic response of two 2D r.c. frames, one bare and one infilled. Finally a real application, on an existing 3D building where dissipative braces available on market are used, is discussed.