• Title/Summary/Keyword: lower structure

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The Performance of Insulation of Noise by Air between Floors According to Structure Systems of Apartment (공동주택 구조형태별 층간 공기전달음 차단 성능)

  • Lee, Byung-Kwon
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2007.05a
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    • pp.1152-1155
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    • 2007
  • Lately concerns about structure have been increased by advantages of floor impact noise, poilitical induction and changeability. Hence, Flat Plate Structure has been constructed increasingly. This study shows the comparison of the performance of sound insulation of Flat Plate Structure System and the existing Wall Structure. For this study, taking the same level organization of Daelim Architectural Environmental Research Center, I found the performance of sound insulation between the upper and lower floors about Wall Structure and Flat Plate Structure. Consequently, the performance of sound insulation between upper and lower floors of Flat Plate Structure was 3-5dB higher was approximately 3-5dB higher than one of Wall Structure. Especially, the performance of sound insulation on the upper floor was 1-3dB higher than on the lower floor. In addition, as the result of comparing radiation sound which radiates from the wall of lower floors with each structure system, Flat Plate Structure was about 4dB higher with Rw than Wall Structure. As we see totally, the performance of sound insulation of Flat Plate Structure is highter than one of the Wall Structure. It is 3-5dB higher and the main reason for this result depends on the existence of the wall which can radiate sound and nonexistence.

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A Basic Study on the Influence of an Understructure on the Seismic Response of a Spatial Structure (공간구조의 지진응답에 대한 연구 하부구조의 영향에 관한 기초적 연구)

  • Jung, Chan-Woo;Jung, Hwan-Mok
    • Proceeding of KASS Symposium
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    • 2005.05a
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    • pp.215-226
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    • 2005
  • To study the influence of an lower part on the seismic response of a spatial structure as the upper part of a structure, as a first step, authors subsititude the upper part and the lower part of a structure to single degree of freedom systems indivisually, and set up structural models connected by them. It is clarified that the mass ratio and the period ratio of an upper part to a lower part are important parameteres to find the amplification or reduction of the sesimic response of an upper part by considering of a lower part.

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Lightning Risk Assessment for Structures Lower than 20m High (높이 20미터 미만인 구조물의 낙뢰리스크 평가)

  • Lee, Ju-Chul;Kim, Gi-Hyun;Lee, Young-Chul
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.26 no.12
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    • pp.21-27
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    • 2012
  • Korean Industrial Standards for lightning protection system complies with IEC standards. However, the standards are applicable only to buildings and structures more than 20 meters in high. Therefore, it is necessary to determine whether lightning protection system should be installed on structures lower than 20 meters high. This paper proposes an efficient method of assessing risk against lightning of structures lower than 20 meters high. The method suggests simplified lightning protection system and provides selecting an appropriate protection level. The suggested method assumes that structure under assessment has no lightning protection system and there is no person around the structure at the moment of lightning stroke. A simplified method of assessing the risk to human within the structure is developed by adopting the general assessment factor. The selection of a protection level is possible by comparing tolerable risk with physical damage risk caused by a direct lightning. Finally, this paper gives ways to establish surge protection measures when a structure with lightning risk is within a radius of 2km from the assessed structure even if this structure requires no lightning protection system.

A Study on Natural Vibration Characteristics of Dome Structure According to Natural Frequency Ratio of Substructure (하부 구조의 고유 진동수비에 따른 돔 구조의 고유 진동 특성에 관한 연구)

  • Park, Kwang-Seob;Kim, Yun-Tae
    • Journal of Korean Association for Spatial Structures
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    • v.18 no.3
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    • pp.75-82
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    • 2018
  • Large space structures exhibit different natural vibration characteristics depending on the aspect ratio of structures such as half-open angle. In addition, since the actual large space structure is mostly supported by the lower structure, it is expected that the natural vibration characteristics of the upper structure and the entire structure will vary depending on the lower structure. Therefore, in this study, the natural vibration characteristics of the dome structure are analyzed according to the natural frequency ratio by controlling the stiffness of the substructure. As the natural frequency of the substructure increases, the natural frequency of the whole structure increases similarly to the natural frequency of the upper structure. Vertical vibration modes dominate at $30^{\circ}$ and $45^{\circ}$, and horizontal vibration modes dominate at $60^{\circ}$ and $90^{\circ}$.

The Nonlinear Behavior Characteristics of the 3D Mixed Building Structures with Variations in the Lower Stories (입체 복합구조물의 하부골조 층수 변화에 따른 비선형 거동특성)

  • 강병두;전대한;김재웅
    • Journal of the Earthquake Engineering Society of Korea
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    • v.6 no.1
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    • pp.55-62
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    • 2002
  • The upper wall-lower frame structures(mixed building structures) are usually composed of shear wall structure in the upper part of structure which is used as residential space and frame structure in the lower part of structure which is used as commercial space centering around the transfer system in the lower part of structure. These structures are characteristics of stiffness irregularity, mass irregularity, and vertical geometric irregularity. The purpose of this study is to investigate the nonlinear response characteristics and the seismic capacity of mixed building structures when the number of stories in the lower frame is varied. The conclusions of this study are following. 1) As the result of push-over analysis of structure such as roof drift(i.e. roof displacement/structural height) and base shear coefficient, when the stories of lower frame system are increased, base shear coefficient is decreased, but roof drift is increased. 2) According to an increase in stories of the lower fame, story drift and ductility ratio of upper wall system are decreased and behavior of upper wall system is closed to elastic. 3) When the stories of lower frame system are increased, the excessive story drift is concentrated on the lower frame system.

Key technologies research on the response of a double-story isolated structure subjected to long-period earthquake motion

  • Liang Gao;Dewen Liu;Yuan Zhang;Yanping Zheng;Jingran Xu;Zhiang Li;Min Lei
    • Earthquakes and Structures
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    • v.26 no.1
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    • pp.17-30
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    • 2024
  • Earthquakes can lead to substantial damage to buildings, with long-period ground motion being particularly destructive. The design of high-performance building structures has become a prominent focus of research. The double-story isolated structure is a novel type of isolated structure developed from base isolated structure. To delve deeper into the building performance of double-story isolated structures, the double-story isolated structure was constructed with the upper isolated layer located in different layers, alongside a base isolated structure for comparative analysis. Nonlinear elastoplastic analyses were conducted on these structures using different ground motion inputs, including ordinary ground motion, near-field impulsive ground motion, and far-field harmonic ground motion. The results demonstrate that the double-story isolated structure can extend the structural period further than the base isolated structure under three types of ground motions. The double-story isolated structure exhibits lower base shear, inter-story displacement, base isolated layer displacement, story shear, and maximum acceleration of the top layer, compared to the base isolated structure. In addition, the double-story isolated structure generates fewer plastic hinges in the frame, causes less damage to the core tube, and experiences smaller overturning moments, demonstrating excellent resistance to overturning and a shock-absorbing effect. As the upper isolated layer is positioned higher, the compressive stress on the isolated bearings of the upper isolated layer in the double-story isolated structure gradually decreases. Moreover, the compressive stress on the isolated bearings of the base isolated layer is lower compared to that of the base isolated structure. However, the shock-absorbing capacity of the double-story isolated structure is significantly increased when the upper isolated layer is located in the middle and lower section. Notably, in regions exposed to long-period ground motion, a double-story isolated structure can experience greater seismic response and reduced shock-absorbing capacity, which may be detrimental to the structure.

A Study on the Spatial Characteristics from the "The Holy Trinity" Fresco Painted by Masaccio (마사치오의 "삼위일체" 벽화에서 나타난 공간적인 특성에 관한 연구)

  • Kim, Seok-Man
    • Journal of architectural history
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    • v.22 no.6
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    • pp.7-22
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    • 2013
  • The purpose of this paper is to study on the spatial characteristics from the "The Holy Trinity" fresco painted by Masaccio in the early Renaissance paintings. The results of this study are as follows. 1. The elevation composition of the "The Holy Trinity" fresco is divided into the upper and lower structure through horizontal axis on horizontal line around vanishing point. The upper structure is composed of vertical axis formed through the disposition of the "Trinity" elements and horizontal axis on horizontal line. The lower structure is composed of the sarcophagus and skeleton in such inside and the altar supported through circular columns of left and right. 2. The section composition of the "The Holy Trinity" fresco is composed of the ceiling structure of cylindrical-shaped vault on upper part around basic square floor plan that is interior space and upper structure. The exterior space and lower structure is placed with sarcophagus in inner part that altar and step is projected as same height and width in the outside direction. 3. The basic floor composition of the "The Holy Trinity" fresco is planned by square shape around structural columns that is placed at corners as symmetry through transverse, longitudinal and diagonal axis. The whole floor composition planned through the altar and step that is in exterior space at front, the apse of round form at rear part and the structure of the middle story concept at interior. 4. The visual aspect of the "The Holy Trinity" fresco is composed of the stable balance in relation with distance and height because the interior and exterior space as well as the upper structure and lower structure is formed by regular proportion system. The elevation angle of visual range was planned to view in detail generally or partially the architectural composition system and element, characters through proper visual distance, center and position.

A Study on the Influence of a supporting structure on the Seismic Response of a Roof Structure (하부구조가 지붕구조의 지진응답에 미치는 영향에 관한 연구)

  • Jung, Chan-Woo;Kang, Joo-Won
    • Journal of Korean Association for Spatial Structures
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    • v.7 no.2 s.24
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    • pp.63-74
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    • 2007
  • Large spatial structures consist of roof structure and its supporting structure. Authors simply call the supporting structure "lower parts" and roof structure "upper parts". To study the influence of an lower part on the seismic response of the upper part of a structure as a first step, authors substitute the upper part and the lower part of the structure to a single degree of freedom system individually, and set up a new 2 DOF structural model connected by them. It is clarified that the mass ratio and the period ratio of an upper part to a lower part are important parameters to find the amplification or reduction of the seismic response of an upper part.

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Development of Conceptual Structure for Clothing Shopping Orientation (의복 쇼핑 성향의 개념적 구조 규명)

  • 김세희;이은영
    • Journal of the Korean Society of Clothing and Textiles
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    • v.28 no.6
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    • pp.830-841
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    • 2004
  • The necessity to understand shopping orientation is increasing. Yet, there has been few research that investigated the conceptual structure of clothing shopping orientation[CSO]. Therefore, the purpose of this study is to develop the conceptual structure of CSO. For that purpose, both documentary and empirical researches were conducted. The documentary research was conducted to develop a theoretical structure model as a basis for exploring the conceptual structure of CSO. The empirical research was conducted to identify and modify the theoretical model so as to develop a conceptual structure model. The data was analyzed using confirmatory factor analysis, exploratory factor analysis, and Pearson's correlation analysis. As a result, a conceptual structure model of CSO was developed. The model consisted of three hierarchical levels of dimensions; upper-dimensions, middle-dimensions and lower-dimensions. The upper-dimensions were composed of 'economic', 'hedonic', and 'convenient' dimensions. Each upper-dimension consisted of middle-dimensions and lower-dimensions. Confirmatory factor analysis was executed to assess the fitness and cross validity of the structure model.

Experimental Study on Natural Period for Arch Structure with Column (하부기둥에 따른 아치구조물의 고유주기 변화에 관한 실험적 연구)

  • Kang, Joo-Won;Seok, Keun-Yung;Lee, Sang-Hoon;Kim, Gee-Cheol
    • Journal of Korean Association for Spatial Structures
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    • v.9 no.2
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    • pp.83-90
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    • 2009
  • The previous studies for dynamic behavior of spatial structure have been zoomed in on roof structure by numerical analytic method. But the roof structure of real spatial structures is supported by lower structure as column and wall. So, when earthquake is occurred, it is predicted that dynamic behavior of roof structure is affected by lower structure. Therefore, on this study, natural period characteristics of arch structures are analyzed according to section, length and the modulus of elasticity of brass column and polycarbonate column and additional mass of roof structure by the scale-down model of arch structure as the most simple structure of spatial structures. The changes of natural periods are generally alike. But, when Polycarbonate column is connected to roof structure, the change of natural period for change of section is relatively large. That means that change of section and section and length of column and additional mass of roof structure have less influence on change of stiffness because the modulus of elasticity of brass is relatively large.

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