• Title/Summary/Keyword: dual frame

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A simplified seismic design method for low-rise dual frame-steel plate shear wall structures

  • Bai, Jiulin;Zhang, Jianyuan;Du, Ke;Jin, Shuangshuang
    • Steel and Composite Structures
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    • v.37 no.4
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    • pp.447-462
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    • 2020
  • In this paper, a simplified seismic design method for low-rise dual frame-steel plate shear wall (SPSW) structures is proposed in the framework of performance-based seismic design. The dynamic response of a low-rise structure is mainly dominated by the first-mode and the structural system can be simplified to an equivalent single degree-of-freedom (SDOF) oscillator. The dual frame-SPSW structure was decomposed into a frame system and a SPSW system and they were simplified to an equivalent F-SDOF (SDOF for frame) oscillator and an equivalent S-SDOF (SDOF for SPSW) oscillator, respectively. The analytical models of F-SDOF and S-SDOF oscillators were constructed based on the OpenSees platform. The equivalent SDOF oscillator (D-SDOF, dual SDOF) for the frame-SPSW system was developed by combining the F-SDOF and S-SDOF oscillators in parallel. By employing the lateral force resistance coefficients and seismic demands of D-SDOF oscillator, the design approach of SPSW systems was developed. A 7-story frame-SPSW system was adopted to verify the feasibility and demonstrate the design process of the simplified method. The results also show the seismic demands derived by the equivalent dual SDOF oscillator have a good consistence with that by the frame-SPSW structure.

Challenges to Telephone Survey Sampling: Frames and Weighting Strategies

  • Kim, Sun-Woong
    • Proceedings of the Korean Statistical Society Conference
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    • 2005.11a
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    • pp.79-84
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    • 2005
  • The growing number of households with only cellular phones and no landline telephones, is decreasing the coverage of the landline frame. Dual frame sample designs are considered which draw phone numbers from the landline and the cellular number frame. Cellular phones may be used as personal or household devices. Weighting strategies appropriate to compensate for unequal probabilities in selecting dual frame samples are proposed. Also, some current issues are discussed.

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Structural Analysis of the Dual Thickness Laser Welded Frame (이종두께 레이저 용접 프레임의 구조해석)

  • 이영신;윤충섭;오재문
    • Computational Structural Engineering
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    • v.10 no.4
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    • pp.165-175
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    • 1997
  • In this paper, the stress, buckling and vibration analyses have been performed for several case with the spot weld stiffened rear side frame, the unstiffened rear side frame and the dual thickness laser weld rear side frame. For stress and vibration analyses, the clamped boundary condition with spring supports are used. But for the buckling analyses, the both ends simply supported boundary conditions are used. For the nummerical analyses, ANSYS 5.0 code is adopted. Maximum stress of the spot weld stiffened rear side frame occurs in the main frame and is 80.9 MPa. Maximum strain is 501 .mu.. The maximum stress of the dual thickness laser weld rear side frame of 1.8mm thickness structure is equal with the stress of spot weld stiffened frame. The weight of dual thickness laser weld frame can be reduced about 17.2%. For the stiffened spot weld rear side frame with both ends simply supported boundary conditon, the bucking load is 52.54 kN. When the thickness of the dual thickness laser weld rear side frame become 1.9mm thickness structure, the buckling load of the stiffenerd rear side frame is equal to that of dual thickness laser weld frame. The reduction of the structure weight is about 5%. The fundamental natural frequency of the stiffened spot weld rear side frame for bending mode is 163.6 Hz and that of the dual thickness laser weld rear side frame is 179.8 Hz.

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SHIFT GENERATED DUAL FRAMES FOR LOCALLY COMPACT ABELIAN GROUPS

  • Ahmadi, Ahmad;Askari-Hemmat, Ataollah
    • Journal of the Korean Mathematical Society
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    • v.49 no.3
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    • pp.571-583
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    • 2012
  • Let $G$ be a metrizable, ${\sigma}$-compact locally compact abelian group with a compact open subgroup. In this paper we define the Gramian and the dual Gramian operators for shift invariant subspaces of $L^2(G)$ and we use them to characterize shift generated dual frames for shift in- variant spaces, which forms a frame for a subspace of $L^2(G)$. We present necessary and sufficient conditions for which standard dual is a unique SG-dual frame of type I and type II.

Response Characteristic of the Dual-frame Passive Control System with the Natural Period Difference between the Strength Resistant Core and Frame Structure (강도저항형 코어와 프레임 구조의 진동주기차를 이용한 듀얼프레임 제진시스템의 응답특성)

  • Kim, Tae Kyung;Choi, Kwang Yong;Oh, Sang Hoon;Ryu, Hong Sik
    • Journal of the Earthquake Engineering Society of Korea
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    • v.19 no.6
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    • pp.273-282
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    • 2015
  • In this study, shaking table test has been carried out for the dual frame passive control system for seismic performance verification of the proposed system. The proposed system was separated into two independent frameworks that are strength resistant core and frame structure by connecting to the damper. Moreover, the seismic performance improvement of the proposed system has been verified by comparing and analyzing the experimental results of the proposed system with an existing core system. As a result of the shaking table test, acceleration and displacement responses of dual-frame vibration control system are decreased than those of the existing strength resistant type core system. In the case of the core system, while the damage was concentrated on the column of first floor, the damage of the dual system was dispersed in each layer. The damage also was concentrated on the damper, almost no damage occurs to the structural members. It has been emphasized that installed dampers in the proposed dual system reduce the input energy of whole structure by absorbing seismic input energy, which leads overall system damage to be reduced.

Response modification factor of dual moment-resistant frame with buckling restrained brace (BRB)

  • Abdollahzadeh, Gholamreza;Banihashemi, Mohammadreza
    • Steel and Composite Structures
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    • v.14 no.6
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    • pp.621-636
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    • 2013
  • Response modification factor is one of the seismic design parameters to consider nonlinear performance of building structures during strong earthquake, in conformity with the point that many seismic design codes led to reduce the loads. In the present paper it's tried to evaluate the response modification factors of dual moment resistant frame with buckling restrained braced (BRB). Since, the response modification factor depends on ductility and overstrength; the nonlinear static analysis, nonlinear dynamic analysis and linear dynamic analysis have been done on building models including multi-floors and different brace configurations (chevron V, invert V, diagonal and X bracing). The response modification factor for each of the BRBF dual systems has been determined separately, and the tentative value of 10.47 has been suggested for allowable stress design method. It is also included that the ductility, overstrength and response modification factors for all of the models were decreased when the height of the building was increased.

Frame Multiresolution Analysis

  • Kim, Hong-Oh;Lim, Jae-Kun
    • Communications of the Korean Mathematical Society
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    • v.15 no.2
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    • pp.285-308
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    • 2000
  • We generalize bi-orthogonal (non-orthogona) MRA to frame MRA in which the family of integer translates of a scaling func-tion forms a frame for the initial ladder space V0. We investigate the internal structure of frame MRA and establish the existence of a dual scaling function, and show that, unlike bi-orthogonal MRA, there ex-ists a frame MRA that has no (frame) 'wavelet'. Then we prove the existence of a dual wavelet under the assumption of the existence of a wavelet and present easy sufficient conditions for the existence of a wavelet. Finally we give a new proof of an equivalent condition for the translates of a function in L2(R) to be a frame of its closed linear span.

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Design of RC dual system building using special seismic detail (내진특수상세를 적용한 RC 이중골조 건물의 설계)

  • Lee, Han-Seon;Ko, Dong-Woo;Sun, Sung-Min
    • Proceedings of the Korea Concrete Institute Conference
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    • 2006.05a
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    • pp.190-193
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    • 2006
  • The definition of the Dual system is that the total seismic force resistance is to be provided by the combination of the moment frame and the shear walls or braced frames in proportion to their stiffness and the moment frame shall be capable of resisting at least 25% of the design force in Korean Building Code 2005 (KBC 2005). But, the definition of moment frame is ambiguous whether the moment frame include the imaginary columns in the shear wall (Case I) or include only the columns outside the shear wall (Case II). 60-story RC building was designed as dual system for Case I and Case II, and the required strength and reinforcement are compared. Moment and axial capacity of the shear wall of Case II decreased about 5% due to the absence of the column in the shear wall. The requirement of upper and bottom reinforcement of slab in Case II increased 13% and 40%, respectively, when compared to those of Case I. The required longitudinal reinforcement in columns for Case II is about 1.5 times larger than that of Case I.

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Redundancy of Dual and Steel Moment Frame Systems under Earthquakes

  • Song, S.H.;Wen, Y.K.
    • Computational Structural Engineering : An International Journal
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    • v.1 no.2
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    • pp.137-137
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    • 2001
  • The reliability/redundancy of structural system has become a serious concern among engineers and researchers after structural failures in Northridge and Kobe earthquakes. The reliability/redundancy factor, ρ, in current codes considers only member force and floor area and has received much criticism from dissatisfied engineers. Within a reliability framework. the redundancy is investigated for dual systems of primary shear walls and secondary moment frames and steel moment frame systems. Probabilistic performance analyses are carried out baled on nonlinear responses under SAC ground motion. The effects of structural configuration, ductilily capacity, 3-D motion, and uncertainty of demand verses capacity are investigated. Important redundancy-contributing factors are identified and a uniform-risk redundancy factor is developed for design. The result are compared with the p factor and its inconsistency is pointed out.

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