• Title/Summary/Keyword: Knowledge Structures

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Conceptual Structural Design Method in Integrated Design System for Tall Buildings (초고층건물의 통합설계시스템에서 개념구조설계법 개발)

  • Song, Hwa-Cheol;Cho, Yong-Soo
    • Journal of Korean Association for Spatial Structures
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    • v.5 no.3 s.17
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    • pp.75-82
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    • 2005
  • The conceptual structural design consists of selecting structural material and form of the building, producing a preliminary dimensional layout. The information such as height of the building use, typical live load, wind velocity, design acceleration, maximum lateral deflection, span, story height is a important factor in conceptual design phase. In this case, the knowledge solutions for past similar problems cam be used in the process of defining and finding a solution to the design problems. In this paper, the conceptual structural design method using case-based reasoning which is intended to assist engineers in the conceptual phase of the structural design of tall buildings is introduced. Inductive retrieval method and nearest-neighbor retrieval method are used for selecting structural system and similar design case, respectively.

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Factors Influencing Social Participation in People with Musculoskeletal Conditions - Applying ICF relevant categories - (ICF 관련 범주에 따른 근골격계질환 장애인의 사회참여 관련요인)

  • Shin, Eun Kyoung;Lee, Han Na
    • Korean Journal of Social Welfare
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    • v.65 no.1
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    • pp.5-31
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    • 2013
  • The principle objective of this study is to determine factors affecting social participation for physically disabled people with musculoskeletal conditions (spinal cord injury, muscular dystrophy, osteogenesis imperfecta, rheumatoid arthritis) in South Korea using ICF relevant categories of the international classification index by WHO. The subjects of this study 352 people with physical disabilities, the data were collected using ICF component(body functions, body structures, activities and participation and environmental factors) and the relevant categories deprived from ICF core sets. The collected data were evaluated with descriptive analysis, ANOVA, correlation analysis, and multiple regression analysis. The results of this study can be summarized as follow. The mental function, Neuromusculoskeletal and movement-related functions, Genitourinary and reproductive functions, Skin and related structures, Learning and applying knowledge, General tasks and demands, and Mobility positively influenced social participation in people with musculoskeletal conditions. However individual factors and environmental factors didn't statistically significant affect on social participation. The implications of the study is to examine by ICF components of universal approach on disability study and utilized the relevant ICF categories as measurement tools.

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Strength of Joint in Floating Structures Constructed with Precast Concrete Modules (프리캐스트 콘크리트 부유식 구조물의 모듈 접합부 강도)

  • Yang, In-Hwan;Kim, Kyung-Cheol
    • Journal of Navigation and Port Research
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    • v.36 no.3
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    • pp.197-204
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    • 2012
  • The behavior of floating structures constructed with precast concrete modules is dependent of the behavior of joints between the concrete modules. To accurately predict the floating structure response under the ultimate loading, knowledge of joint behavior is essential. This study aims to investigate the structural behavior of concrete module joints under various configuration of joint and confining stress levels. The shear behavior, shear capacity and crack patterns of shear keys in concrete module have been studied. Test results indicated that the shear capacity of joints increased as shear key inclination increased. In addition, shear capacity of concrete module joint increased with the increase of confining stress levels. The test results were compared with the AASHTO design recommendations. The AASHTO design recommendations underestimated the shear strength of test specimens.

Isoforms, structures, and functions of versatile spectraplakin MACF1

  • Hu, Lifang;Su, Peihong;Li, Runzhi;Yin, Chong;Zhang, Yan;Shang, Peng;Yang, Tuanmin;Qian, Airong
    • BMB Reports
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    • v.49 no.1
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    • pp.37-44
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    • 2016
  • Spectraplakins are crucially important communicators, linking cytoskeletal components to each other and cellular junctions. Microtubule actin crosslinking factor 1 (MACF1), also known as actin crosslinking family 7 (ACF7), is a member of the spectraplakin family. It is expressed in numerous tissues and cells as one extensively studied spectraplakin. MACF1 has several isoforms with unique structures and well-known function to be able to crosslink F-actin and microtubules. MACF1 is one versatile spectraplakin with various functions in cell processes, embryo development, tissue-specific functions, and human diseases. The importance of MACF1 has become more apparent in recent years. Here, we summarize the current knowledge on the presence and function of MACF1 and provide perspectives on future research of MACF1 based on our studies and others. [BMB Reports 2016; 49(1): 37-44]

A one-dimensional model for impact forces resulting from high mass, low velocity debris

  • Paczkowski, K.;Riggs, H.R.;Naito, C.J.;Lehmann, A.
    • Structural Engineering and Mechanics
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    • v.42 no.6
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    • pp.831-847
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    • 2012
  • Impact from water-borne debris during tsunami and flood events pose a potential threat to structures. Debris impact forces specified by current codes and standards are based on rigid body dynamics, leading to forces that are dependent on total debris mass. However, shipping containers and other debris are unlikely to be rigid compared to the walls, columns and other structures that they impact. The application of a simple one-dimensional model to obtain impact force magnitude and duration, based on acoustic wave propagation in a flexible projectile, is explored. The focus herein is on in-air impact. Based on small-scale experiments, the applicability of the model to predict actual impact forces is investigated. The tests show that the force and duration are reasonably well represented by the simple model, but they also show how actual impact differs from the ideal model. A more detailed three-dimensional finite element model is also developed to understand more clearly the physical phenomena involved in the experimental tests. The tests and the FE results reveal important characteristics of actual impact, knowledge of which can be used to guide larger scale experiments and detailed modeling. The one-dimensional model is extended to consider water-driven debris as well. When fluid is used to propel the 1-D model, an estimate of the 'added mass' effect is possible. In this extended model the debris impact force depends on the wave propagation in the two media, and the conditions under which the fluid increases the impact force are discussed.

Structural and Mechanistic Insights into the Tropism of Epstein-Barr Virus

  • Mohl, Britta S.;Chen, Jia;Sathiyamoorthy, Karthik;Jardetzky, Theodore S.;Longnecker, Richard
    • Molecules and Cells
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    • v.39 no.4
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    • pp.286-291
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    • 2016
  • Epstein-Barr virus (EBV) is the prototypical ${\gamma}$-herpesvirus and an obligate human pathogen that infects mainly epithelial cells and B cells, which can result in malignancies. EBV infects these target cells by fusing with the viral and cellular lipid bilayer membranes using multiple viral factors and host receptor(s) thus exhibiting a unique complexity in its entry machinery. To enter epithelial cells, EBV requires minimally the conserved core fusion machinery comprised of the glycoproteins gH/gL acting as the receptor-binding complex and gB as the fusogen. EBV can enter B cells using gp42, which binds tightly to gH/gL and interacts with host HLA class II, activating fusion. Previously, we published the individual crystal structures of EBV entry factors, such as gH/gL and gp42, the EBV/host receptor complex, gp42/HLA-DR1, and the fusion protein EBV gB in a postfusion conformation, which allowed us to identify structural determinants and regions critical for receptor-binding and membrane fusion. Recently, we reported different low resolution models of the EBV B cell entry triggering complex (gHgL/gp42/HLA class II) in "open" and "closed" states based on negative-stain single particle electron microscopy, which provide further mechanistic insights. This review summarizes the current knowledge of these key players in EBV entry and how their structures impact receptor-binding and the triggering of gB-mediated fusion.

Development and testing of a composite system for bridge health monitoring utilising computer vision and deep learning

  • Lydon, Darragh;Taylor, S.E.;Lydon, Myra;Martinez del Rincon, Jesus;Hester, David
    • Smart Structures and Systems
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    • v.24 no.6
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    • pp.723-732
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    • 2019
  • Globally road transport networks are subjected to continuous levels of stress from increasing loading and environmental effects. As the most popular mean of transport in the UK the condition of this civil infrastructure is a key indicator of economic growth and productivity. Structural Health Monitoring (SHM) systems can provide a valuable insight to the true condition of our aging infrastructure. In particular, monitoring of the displacement of a bridge structure under live loading can provide an accurate descriptor of bridge condition. In the past B-WIM systems have been used to collect traffic data and hence provide an indicator of bridge condition, however the use of such systems can be restricted by bridge type, assess issues and cost limitations. This research provides a non-contact low cost AI based solution for vehicle classification and associated bridge displacement using computer vision methods. Convolutional neural networks (CNNs) have been adapted to develop the QUBYOLO vehicle classification method from recorded traffic images. This vehicle classification was then accurately related to the corresponding bridge response obtained under live loading using non-contact methods. The successful identification of multiple vehicle types during field testing has shown that QUBYOLO is suitable for the fine-grained vehicle classification required to identify applied load to a bridge structure. The process of displacement analysis and vehicle classification for the purposes of load identification which was used in this research adds to the body of knowledge on the monitoring of existing bridge structures, particularly long span bridges, and establishes the significant potential of computer vision and Deep Learning to provide dependable results on the real response of our infrastructure to existing and potential increased loading.

Behaviour and design of guyed pre-stressed concrete poles under downbursts

  • Ibrahim, Ahmed M.;El Damatty, Ashraf A.
    • Wind and Structures
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    • v.29 no.5
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    • pp.339-359
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    • 2019
  • Pre-stressed concrete poles are among the supporting systems used to support transmission lines. It is essential to protect transmission line systems from harsh environmental attacks such as downburst wind events. Typically, these poles are designed to resist synoptic wind loading as current codes do not address high wind events in the form of downbursts. In the current study, the behavior of guyed pre-stressed concrete Transmission lines is studied under downburst loads. To the best of the authors' knowledge, this study is the first investigation to assess the behaviour of guyed pre-stressed concrete poles under downburst events. Due to the localized nature of those events, identifying the critical locations and parameters leading to peak forces on the poles is a challenging task. To overcome this challenge, an in-house built numerical model is developed incorporating the following: (1) a three-dimensional downburst wind field previously developed and validated using computational fluid dynamics simulations; (2) a computationally efficient analytical technique previously developed and validated to predict the non-linear behaviour of the conductors including the effects of the pretension force, sagging, insulator's stiffness and the non-uniform distribution of wind loads, and (3) a non-linear finite element model utilized to simulate the structural behaviour of the guyed pre-stressed concrete pole considering material nonlinearity. A parametric study is conducted by varying the downbursts locations relative to the guyed pole while considering three different span values. The results of this parametric study are utilized to identify critical downburst configurations leading to peak straining actions on the pole and the guys. This is followed by comparing the obtained critical load cases to new load cases proposed to ASCE-74 loading committee. A non-linear failure analysis is then conducted for the three considered guyed pre-stressed concrete transmission line systems to determine the downburst jet velocity at which the pole systems fail.

The effect of wollastonite powder with pozzolan micro silica in conventional concrete containing recycled aggregate

  • Dinh-Cong, Du;Keykhosravi, Mohammad. H.;Alyousef, Rayed;Salih, Musab N.A.;Nguyen, Hoang;Alabduljabbar, Hisham;Alaskar, Abdulaziz;Alrshoudi, Fahed;Poi-Ngian, Shek
    • Smart Structures and Systems
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    • v.24 no.4
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    • pp.541-552
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    • 2019
  • Construction development and greenhouse gas emissions have globally required a strategic management to take some steps to stain and maintain the environment. Nowadays, recycled aggregates, in particular ceramic waste, have been widely used in concrete structures due to the economic and environmentally friendly solution, requiring the knowledge of recycled concrete. Also, one of the materials used as a substitute for concrete cement is wollastonite mineral to decrease carbon dioxide (CO2) from the cement production process by reducing the concrete consumption in concrete. The purpose of this study is to investigate the effect of wollastonite on the mechanical properties and durability of conventional composite concrete, containing recycled aggregates such as compressive strength, tensile strength (Brazilian test), and durability to acidic environment. On the other hand, in order to determine the strength and durability of the concrete, 5 mixing designs including different wollastonite values and recovered aggregates including constant values have been compared to the water - cement ratio (w/c) constant in all designs. The experimental results have shown that design 5 (containing 40% wollastonite) shows only 6.1% decrease in compressive strength and 4.9% decrease in tensile strength compared to the control plane. Consequently, the use of wollastonite powder to the manufacturing of conventional structural concrete containing recycled ceramic aggregates, in addition to improving some of the properties of concrete are environmentally friendly solutions, providing natural recycling of materials.

Effect of low frequency motion on the performance of a dynamic manual tracking task

  • Burton, Melissa D.;Kwok, Kenny C.S.;Hitchcock, Peter A.
    • Wind and Structures
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    • v.14 no.6
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    • pp.517-536
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    • 2011
  • The assessment of wind-induced motion plays an important role in the development and design of the majority of today's structures that push the limits of engineering knowledge. A vital part of the design is the prediction of wind-induced tall building motion and the assessment of its effects on occupant comfort. Little of the research that has led to the development of the various international standards for occupant comfort criteria have considered the effects of the low-frequency motion on task performance and interference with building occupants' daily activities. It has only recently become more widely recognized that it is no longer reasonable to assume that the level of motion that a tall building undergoes in a windstorm will fall below an occupants' level of perception and little is known about how this motion perception could also impact on task performance. Experimental research was conducted to evaluate the performance of individuals engaged in a manual tracking task while subjected to low level vibration in the frequency range of 0.125 Hz-0.50 Hz. The investigations were carried out under narrow-band random vibration with accelerations ranging from 2 milli-g to 30 milli-g (where 1 milli-g = 0.0098 $m/s^2$) and included a control condition. The frequencies and accelerations simulated are representative of the level of motion expected to occur in a tall building (heights in the range of 100 m -350 m) once every few months to once every few years. Performance of the test subjects with and without vibration was determined for 15 separate test conditions and evaluated in terms of time taken to complete a task and accuracy per trial. Overall, the performance under the vibration conditions did not vary significantly from that of the control condition, nor was there a statistically significant degradation or improvement trend in performance ability as a function of increasing frequency or acceleration.