• Title/Summary/Keyword: Structural members

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Substructuring technique for local vibration of building structures (부분구조법에 의한 건축물의 국부진동해석)

  • 이동근;안상경;김진구
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 1998.04a
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    • pp.373-380
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    • 1998
  • Generally the excessive caused by isolated sources in localized to members closely located to the vibration sources. In this case it may not be economical to model the whole structure to obtain the responses of a specific member. In this study, a substructuring technique has been used for local vibration of a framed structure. The boundary conditions of members selected are determined by condensing the degrees of freedom of the remaining members. Fixed and hinged boundary condition are also assumed for comparison. According to the results, the substructuring technique is quite efficient in predicting the responses of a structure on which the vibration source in located, but is not very reliable for the members located for away from the source.

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Analytic Hysteretic Model of Reinforced Concrete Members (철근콘크리트 부재의 해석적 이력모델)

  • 정영수
    • Computational Structural Engineering
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    • v.4 no.1
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    • pp.133-142
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    • 1991
  • A mathematical hysteretic model has been developed to analytically reproduce the experimental hysteretic behavior of reinforced concrete members. This mode[2, 3] can simulate the nonlinear response of reinforced concrete members with sufficient accuacy, which are characterized by following important hysteretic behaviors: stiffness degradation, strength deterioration and shear effect. In order to illustrate the capabilities of the proposed mathematical model, numerical examples are presented with the reproduction of experimental hysteretic behavior of RC members and frames.

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Analysis of Hysteretic Behavior of R/C Members subjected to Load Reversals - Single component model having the finite size of plastic regions - (반복하중을 받는 철근콘크리트 부재의 이력거동 해석 -유한한 소성력을 갖는 일원성분 모델을 사용하여-)

  • 김윤일;이리형;서수연;천영수
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 1990.04a
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    • pp.6-11
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    • 1990
  • Inelastic behavior of reinforced concrete members is very complex and affected by many factors. Therefore, though using the finite element method which is good to predict the response of R/C member, it has to be proceeded to model these factors appropriately which have influence on the behavioral characteristics of reinforced concrete members. The proposed model consists of the physical single component model having the finite size of plastic regions and the hysteretic rules, by regressing experimental data, which can idealize the hysteretic behavior of R/C member under inelastic cyclic loads. This study confirms the accuracy of the developed analytical model through comparison with the test results of R/C members having a variety of shear-to-depth ratio and maximum shear stress.

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Investigation of nonlinear behaviour of reinforced concrete frames having different stiffening members

  • Gursoy, Senol
    • Computers and Concrete
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    • v.13 no.5
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    • pp.679-694
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    • 2014
  • The selected carrier systems of reinforced concrete frame buildings are quite important on structural damages. In this study are examined comparatively nonlinear behaviours of reinforced concrete frames which having different stiffening members under a horizontal load. In that respect, the study consists of six parametric models. With this purpose, nonlinear structural analyses of reinforced concrete frames which having different stiffening members were carried out with LUSAS which uses the finite element method. Thus, some conclusions and recommendations to mitigate the damage of reinforced concrete buildings in the future designs are aimed to present. The obtained results revealed that in terms of performance, the x-shaped diagonal elements can be used as an option to shear walls. In addition, it was found that frame-2, frame-3 and frame-4 showed a better performance than traditional frame system (frame-1).

Tension Stiffening Effects of MMA-Modified Polymer Concrete (MMA 개질 폴리머 콘크리트의 인장증강 효과)

  • Yeon Kyu Seok;Kweon Taek Jeong;Jeong jung Ho;Jin Xing Qi
    • Proceedings of the Korea Concrete Institute Conference
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    • 2004.05a
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    • pp.304-307
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    • 2004
  • Direct tensile tests were carried out for the tensile members of MMA-modified polymer concrete with different steel kinds and steel diameters and steel ratios to figure out the effect of tensile strength of polymer concrete. In the experiments, MMA-modified polymer concrete with $1000\;kgf/cm^2$ of compressive strength, steel with $5200\;kgf/cm^2$ of tensile strength, and the tensile members with 100 cm of constant length were used. Experimental results showed that, regardless of steel kinds, diameters and steel content, the strain energy exerted by concrete till the initial crack was $14-15\%$ of the total energy till the point of yield: The energy was much larger than the one of high-strength cement concrete. The behaviors of tensile members of MMA-modified polymer concrete were in relatively good agreement with the model suggested by Gupta-Maestrini (1990), which was idealized by the effective tensile stress-strain relationship of concrete and the load-strain relationship of members, while those showed a big difference from CEB-FIP model and ACI-224 equation suggested for the load-displacement relationship that was defined as the cross sectional stiffness of effective axis. Modified ACI-224 model code about the load-displacement relationship for the tensile members of MMA-modified polymer concrete and theoretical equation for the polymer concrete tensile stiffness of polymer concrete suggested through the results of this study are expected to be used in an accurate structural analysis and resign for the polymer concrete structural members.

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Structural insights of homotypic interaction domains in the ligand-receptor signal transduction of tumor necrosis factor (TNF)

  • Park, Young-Hoon;Jeong, Mi Suk;Jang, Se Bok
    • BMB Reports
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    • v.49 no.3
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    • pp.159-166
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    • 2016
  • Several members of tumor necrosis factor receptor (TNFR) superfamily that these members activate caspase-8 from death-inducing signaling complex (DISC) in TNF ligand-receptor signal transduction have been identified. In the extrinsic pathway, apoptotic signal transduction is induced in death domain (DD) superfamily; it consists of a hexahelical bundle that contains 80 amino acids. The DD superfamily includes about 100 members that belong to four subfamilies: death domain (DD), caspase recruitment domain (CARD), pyrin domain (PYD), and death effector domain (DED). This superfamily contains key building blocks: with these blocks, multimeric complexes are formed through homotypic interactions. Furthermore, each DD-binding event occurs exclusively. The DD superfamily regulates the balance between death and survival of cells. In this study, the structures, functions, and unique features of DD superfamily members are compared with their complexes. By elucidating structural insights of DD superfamily members, we investigate the interaction mechanisms of DD domains; these domains are involved in TNF ligand-receptor signaling. These DD superfamily members play a pivotal role in the development of more specific treatments of cancer.

Ultimate Strength of Dented Tubular Members(2nd report) -under Bending Loads- (Dent 손상을 갖는 원통부재의 최종강도에 관한 연구(제2보) -굽힘 하중을 받는 경우-)

  • Nho, In-Sik;Chun, Tae-Byng;Cho, Byung-Sam
    • Journal of the Society of Naval Architects of Korea
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    • v.41 no.6
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    • pp.56-64
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    • 2004
  • Several types of steel structures which are employed in offshore petroleum activities are constructed with tubular members. These structures are usually subjected to various types of loads such as normal functional loads and environmental loads. Furthermore, accidental loads may also act on the leg or bracing members due to supply boat collisions and objects droppings from platform decks. The extent of damage caused by these loads ranges from total collapse of the structure to small damage which may not have serious consequence at the time of accident. To make optimal design decisions regarding structural safety and economical efficiency, it is very important to be able to assess the influence of damages on the performance of damaged structural members. In the End report, a series of calculations is performed to study the effects of different parameters on the load carrying capacity of such damaged members under pure bending. And the results of analysis are compared with experiment results.

Tension Stiffening of Reinforced Polymer Concrete Tension member (철근보강 폴리머 콘크리트 인장부재의 인장강성)

  • Yeon, Kyu-Seok;Jin, Nan-Ji;Jo, Kyu-Woo;Kweon, Taek-Jong
    • Proceedings of the Korean Society of Agricultural Engineers Conference
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    • 2003.10a
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    • pp.387-390
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    • 2003
  • Direct tensile tests were carried out for the tensile members of steel-reinforced polymer concrete with different steel diameters and steel ratios to figure out the effect of tensile strength of polymer concrete. In the experiments, polymer concrete with $1000kgf/cm^2$ of compressive strength, steel with $5200kgf/cm^2$ of tensile strength, and the tensile members with 100 cm of constant length were used. Experimental results showed that, regardless of steel diameters and steel content, the strain energy exerted by concrete till the initial crack was 14-15% of the total energy till the point of yield: The energy was much larger than the one of high-strength cement concrete. The behaviors of tensile members of steel-reinforced polymer concrete were in relatively good agreement with the model suggested by Gupta-Maestrini (1990), which was idealized by the effective tensile stress-strain relationship of concrete and the load-strain relationship of members, while those showed a big difference from CEB-FIP model and ACI-224 equation suggested for the load-displacement relationship that was defined as the cross sectional stiffness of effective axis. Modified ACI-224 model code about the load-displacement relationship for the tensile members of steel-reinforced polymer concrete and theoretical equation for the polymer concrete tensile stiffness of polymer concrete suggested through the results of this study are expected to be used in an accurate structural analysis and design for the polymer concrete structural members.

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The Family Characteristics Affecting the Socio-Cultural Adjustment of North Korean Defectors (가족특성에 따른 새터민의 사회문화적 적응)

  • Chin, Mee-Jung;Yi, Soon-Hyung
    • Journal of the Korean Home Economics Association
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    • v.45 no.5
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    • pp.63-74
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    • 2007
  • As the number of North Koreans defectors entering South Korea with their family members increases, it becomes more important to explore the family characteristics that facilitate their adjustment. The data used in the present study was collected from a survey of 195 North Korean defectors. The aim of this study was to investigates how the structural and relational aspects of family influence the socio-cultural adjustment of North Korean defectors. The structural characteristics of family life included whether or not the defectors exited with their family members, whether they were living with family members, and whether they were living with family members under the age of 18. The relational characteristics included family cohesion and adaptability. The study results showed that living with young family members was negatively associated with the social activity restriction problems commonly perceived by North Korean defectors. Family cohesion was also negatively associated with the social activity restriction problems and positively associated with the social isolation problems. The results of this study also showed that family adaptability was not significantly associated with any socio-cultural adjustment problems.

Towards a Structure-Function Relationship for Vascular Endothelial Growth Factor-B (VEGF-B)

  • Scrofani, Sergio D.B.;Nash, Andrew D.
    • Journal of Microbiology and Biotechnology
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    • v.11 no.4
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    • pp.543-551
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    • 2001
  • The vascular endothelial growth factor (VEGF), or VEGF-A, is intimately involved in both physiological and pathological forms of angiogenesis. VEGF-A is now recognized as the founding member of a family of growth factors that has expanded to include VEGF-B, VEGF-C, VEGF-D, VEGF-E, and placental growth factor (PIGF). This family of cytokines binds differentially to at least three receptor tyrosine kinases, however, the extent to which family members other than VEGF-A contribute to physiological and pathological angiogenesis remains unclear. Issues that are of relevance include uncertainty regarding the consequences of signaling through VEGF - RI in particular, and the ability of some family members to heterodimerize, leading to the possibility ofheterodimeric receptor complexes. Structural characterization is one approach that can be used to address these issues, however, the vast majority of previous structure-function studies have only focused on VEGF-A. While these studies may provide some clues regarding the structural basis of the interaction of other family members with their receptors, studies using the ligands themselves are clearly required if highly specific interactions are to be revealed. With the recent progress toward refolding and purifying substantial' quantities of other VEGF family members, such structural studies are now possible. Here, these ~ssues are addressed with a particular emphasis on VEGF-B and its receptors.

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