• Title/Summary/Keyword: Physical Infrastructure

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Local buckling behaviour of steel plate elements supported by a plastic foam material

  • Mahendran, M.;Jeevaharan, M.
    • Structural Engineering and Mechanics
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    • v.7 no.5
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    • pp.433-445
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    • 1999
  • Sandwich panels comprising steel facings and a polystyrene foam core are increasingly used as roof and wall claddings in buildings in Australia. When they are subjected to loads causing bending and/or axial compression, the steel plate elements of their profiled facing are susceptible to local buckling. However, when compared to panels with no foam core, they demonstrate significantly improved local buckling behaviour because they are supported by foam. In order to quantify such improvements and to validate the use of available design buckling stress formulae, an investigation using finite element analyses and laboratory experiments was carried out on steel plates that are commonly used in Australia of varying yield stress and thickness supported by a polystyrene foam core. This paper presents the details of this investigation, the buckling results and their comparison with available design buckling formulae.

Inelastic two-degree-of-freedom model for roof frame under airblast loading

  • Park, Jong Yil;Krauthammer, Theodor
    • Structural Engineering and Mechanics
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    • v.32 no.2
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    • pp.321-335
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    • 2009
  • When a roof frame is subjected to the airblast loading, the conventional way to analyze the damage of the frame or design the frame is to use single degree of freedom (SDOF) model. Although a roof frame consists of beams and girders, a typical SDOF analysis can be conducted only separately for each component. Thus, the rigid body motion of beams by deflections of supporting girders can not be easily considered. Neglecting the beam-girder interaction in the SDOF analysis may cause serious inaccuracies in the response values in both Pressure-Impulse curve (P-I) and Charge Weight-Standoff Diagrams (CWSD). In this paper, an inelastic two degrees of freedom (TDOF) model is developed, based on force equilibrium equations, to consider beam-girder interaction, and to assess if the modified SDOF analysis can be a reasonable design approach.

Pseudo plastic zone analysis of steel frame structures comprising non-compact sections

  • Avery, P.;Mahendran, M.
    • Structural Engineering and Mechanics
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    • v.10 no.4
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    • pp.371-392
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    • 2000
  • Application of "advanced analysis" methods suitable for non-linear analysis and design of steel frame structures permits direct and accurate determination of ultimate system strengths, without resort to simplified elastic methods of analysis and semi-empirical specification equations. However, the application of advanced analysis methods has previously been restricted to steel frames comprising only compact sections that are not influenced by the effects of local buckling. A concentrated plasticity method suitable for practical advanced analysis of steel frame structures comprising non-compact sections is presented in this paper. The pseudo plastic zone method implicitly accounts for the effects of gradual cross-sectional yielding, longitudinal spread of plasticity, initial geometric imperfections, residual stresses, and local buckling. The accuracy and precision of the method for the analysis of steel frames comprising non-compact sections is established by comparison with a comprehensive range of analytical benchmark frame solutions. The pseudo plastic zone method is shown to be more accurate and precise than the conventional individual member design methods based on elastic analysis and specification equations.

The Proxy Variables Selection of Vulnerability Assessment for Agricultural Infrastructure According to Climate Change (논문 - 기후변화에 따른 농업생산기반 재해 취약성 평가를 위한 대리변수 선정)

  • Kim, Sung-Jae;Park, Tae-Yang;Kim, Sung-Min;Kim, Sang-Min
    • KCID journal
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    • v.18 no.2
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    • pp.33-42
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    • 2011
  • Climate change has impacts on not only the average temperature rise but also the intensity and frequency of extreme events such as flood and drought. It is also expected that the damages on agricultural infrastructure will be increased resulting from increased rainfall intensity and frequency caused by climate change. To strengthen the climate change adaptation capacity, it is necessary to identify the vulnerability of a given society's physical infrastructures and to develop appropriate adaptation strategies with infrastructure management because generally facilities related to human settlements are vulnerable to climate changes and establishing an adaptive public infrastructure would reduce the damages and the repair cost. Therefore, development of mitigation strategies for agricultural infrastructure against climatic hazard is very important, but there are few studies on agricultural infrastructure vulnerability assessment and adaptation strategies. The concept of vulnerability, however, is difficult to functionally define due to the fact that vulnerability itself includes many aspects (biological, socioeconomic, etc.) in various sectors. As such, much research on vulnerability has used indicators which are useful for standardization and aggregation. In this study, for the vulnerability assessment for agricultural infrastructure, 3 categories of climate exposure, sensitivity, and adaptation capacity were defined which are composed of 16 sub-categories and 49 proxy variables. Database for each proxy variables was established based on local administrative province. Future studies are required to define the weighting factor and standardization method to calculate the vulnerability indicator for agricultural infrastructure against climate change.

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A Study on Implementaion of the GIS Based u-City urban Infrastructures (GIS기반 u-City 도시 인프라 구축에 관한 연구)

  • O, Jong-U;O, Seung-Hun
    • 한국디지털정책학회:학술대회논문집
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    • 2006.12a
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    • pp.379-386
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    • 2006
  • The purpose of this paper is to analyze the implementation of the GIS infrastructure systems for the u-City, GIS base u-City represents spatial information derived fields, such as geographical distribution of the urban boundaries, physical configuration of the urban locations and cultural characteristics of the urban history. These three aspects relate to urban infrastructure systems implementation, urban monitoring center implementation, and spatial database implementation. In terms of the GIS based u-Ci쇼 urban infrastructure implementation systems, the u-City depends on IT contents and spatial features. IT contents are strongly related to IT839 strategy due to the national agenda is "u-Korea". GIS should contribute to u-City construction through the spatial analyses methods. For these methods various GIS functions will guide to u-City's distribution, location, and characteristics of urbanization. The infrastructure consists of road and road facilities, underground facilities, related agencies facilities, dispatch systems, environmental systems, and urban planning. These six units of the urban infrastructures have spatial databases that consist of spatial configuration, such as dots, lines, and polygons in order to draw the spatial distribution of the u-City GIS based u-City urban infrastructure implementation systems should deal with It convergence to generate fusion affects.

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Evaluation of the Level of Water Welfare in 24 Local Governments in Deagu·Gyeongsangbukdo using Statistical Yearbook (통계연보를 활용한 대구·경북지역 24개 지자체의 물복지 수준 평가)

  • Lee, Do Kyeong;Ahn, Seung Seop;Park, Ki bum
    • Journal of Environmental Science International
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    • v.30 no.11
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    • pp.937-944
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    • 2021
  • In this study, water resource topics, infrastructure, water supply, users, and economic indicators based on statistical annual standards for evaluating water welfare were selected by examining domestic and foreign water resource-related indicators. The level of water welfare was evaluated relative to 23 cities and counties in Daegu and Gyeongsangbuk-do using data from the Statistical yearbook, and places with high value of indicators urbanization and large populations were excellent in the infrastructure field, but overall analysis showed that small and medium-sized cities had higher levels. It is judged that it is necessary to develop continuous research and indicators that can evaluate and quantify the level of physical welfare that the people can feel by utilizing the results of this study. In future studies, it is necessary to systematically evaluate the level of water welfare by local governments in Korea through more diverse evaluation items and detailed indicators for each item so that it can be used as basic data for realizing water welfare.

Evaluation of the Impact of Abandoned Channel Restoration on Zaco platypus habitat using the Physical Habitat Simulation: A Case Study of the Cheongmi-cheon Stream in Korea (물리서식처 모의를 이용한 구하도 복원이 피라미의 서식처에 미치는 영향 평가: 청미천 연구 사례)

  • Kim, Seung Ki;Choi, Sung-Uk
    • Ecology and Resilient Infrastructure
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    • v.6 no.2
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    • pp.101-108
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    • 2019
  • This study investigated the impact of abandoned channel restoration on fish habitat using the physical habitat simulation. The study area is a 1.2 km long reach of the Cheongmi-cheon stream. In the study area, the restoration of the abandoned channel was carried out from July 2012 to December 2105. Physical habitat simulations were carried out for both cases before and after the restoration. The River2D model and habitat suitability curve were used for hydraulic and habitat simulations, respectively. Zacco platypus, which is a dominant fish species in the study area, was selected as target fish for the physical habitat simulation. Hydraulic simulations were carried out before and after restoration for various discharges. Then, composite suitability index and weighted usable area were calculated before and after restoration and changes in the physical habitat of Zacco platypus were discussed. Simulation results indicated that the abandoned channel restoration is effective in creating fish habitat and mitigating the degradation of fish habitat from the high flow condition.

The Proposal of Debrisflow Investigation (토석류 재해 조사법의 제안)

  • Choi, Hui-Rim;Chang, Bhum-Soo;Lee, Wang-Gon;Park, Sang-Duk
    • Proceedings of the Korean Geotechical Society Conference
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    • 2009.03a
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    • pp.1100-1106
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    • 2009
  • A debris flow is known as that flood and landslide of water cause much physical human damages worldwide to complex natural disaster that happen combining and happy event is happening mainly in urgent mountains area in domestic. Because happen about debris flow that happen from each place every year and is drift, mechanism of accumulation definitely make clear and great many damage is not running out. Must grasp actual conditions of priority debris flow to need debris flow prevention countermeasure and lay countermeasure to take away damage by debris flow. Because collecting actual conditions of debris flow that happen by objective investigation methods and accuracy, proposed about investigation calamity investigation method so that can calculate debris flow damage and prepare in subsequentness damage.

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Towards Open Interfaces of Smart IoT Cloud Services

  • Kim, Kyoung-Sook;Ogawa, Hirotaka
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2016.05a
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    • pp.235-238
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    • 2016
  • With the vision of Internet of Things (IoT), physical world itself is becoming a connected information system on the Internet and cyber world is computing as a physical act to sense and respond to real-world events collaboratively. The systems that tightly interlink the cyber and physical worlds are often referred to as Smart Systems or Cyber-Physical Systems. Smart IoT Clouds aim to provide a cyber-physical infrastructure for utility (pay-as-you-go) computing to easily and rapidly build, modify and provision auto-scale smart systems that continuously monitor and collect data about real-world events and automatically control their environment. Developing specifications for service interoperability is critical to enable to achieve this vision. In this paper, we bring an issue to extend Open Cloud Computing Interface for uniform, interoperable interfaces for Smart IoT Cloud Services to access services and build a smart system through orchestrating the cloud services.

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