• Title/Summary/Keyword: Potential Rise

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A Study on risk management measurers about High-rise APT (고층아파트 위험관리 방안)

  • Kim, Jong Won
    • Journal of the Society of Disaster Information
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    • v.9 no.2
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    • pp.178-187
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    • 2013
  • This paper studied the potential risk of high-rise apartment by analysis of the loss ratio of housing fire insurance, statistics related high-rise apartment fire, and the insured amount of housing fire insurance, and, found that it is so high and need the improvement of risk management measures for high-rise apartment. Accordingly, the study recommend the composit risk management measures including preventing of fire expanding for higher stories, a shelter for people of hire-rise apartment, and sprinkler protection, etc. Also as risk transfer measures, the composit risk measures for high-rise apartment includes the full insurance of housing fire insurance, third party property liability insurance, and development of endorsement for special risk such as a typhoon, liability etc.

An Analysis on Rise of Rail Potential And A Study on Control Method for It in DC Feeding System (직류급전계통에서의 레일전위 상승 분석 및 억제 방안 연구)

  • Min, Myung-Hwan;Jung, Ho-Sung;Park, Young;Kim, Hyeng-Chul;Shin, Myong-Chul
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.60 no.3
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    • pp.680-685
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    • 2011
  • Nowadays, in metropolitan railroad, DC feeding system is being generally applied. In order to reduce damages of electro-chemical corrosion caused by stray current and leakage current, in DC feeding system, rail is used as negative-polarity return conductor for traction load current. However, it has problem of rail potential increase and there are no adequate measures to prevent it in domestic. In this paper, we presented fundamental theory and related standards about rail potential increase. And then, we analyzed field testing data and simulated a variety of operations by using PSCAD/EMTDC as an analysis program of power system. In addition, voltage control device is suggested to prevent accidents caused by rail potential increase.

Semi-active damped outriggers for seismic protection of high-rise buildings

  • Chang, Chia-Ming;Wang, Zhihao;Spencer, Billie F. Jr.;Chen, Zhengqing
    • Smart Structures and Systems
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    • v.11 no.5
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    • pp.435-451
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    • 2013
  • High-rise buildings are a common feature of urban cities around the world. These flexible structures frequently exhibit large vibration due to strong winds and earthquakes. Structural control has been employed as an effective means to mitigate excessive responses; however, structural control mechanisms that can be used in tall buildings are limited primarily to mass and liquid dampers. An attractive alternative can be found in outrigger damping systems, where the bending deformation of the building is transformed into shear deformation across dampers placed between the outrigger and the perimeter columns. The outrigger system provides additional damping that can reduce structural responses, such as the floor displacements and accelerations. This paper investigates the potential of using smart dampers, specifically magnetorheological (MR) fluid dampers, in the outrigger system. First, a high-rise building is modeled to portray the St. Francis Shangri-La Place in Philippines. The optimal performance of the outrigger damping system for mitigation of seismic responses in terms of damper size and location also is subsequently evaluated. The efficacy of the semi-active damped outrigger system is finally verified through numerical simulation.

An Investigation of Effects of Fuel Stratification and Cooled EGR on DME HCCI Engine's Operating Ranges by Numerical Analysis (농도성층화와 Cooled EGR이 DME HCCI 엔진의 운전영역에 미치는 영향에 관한 수치해석)

  • Jeong, Dong-Won;Amarbayar, D.;Lim, Ock-Taeck
    • Journal of Hydrogen and New Energy
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    • v.21 no.2
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    • pp.129-135
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    • 2010
  • Homogeneous charge compression ignition (HCCI) engines have the potential to provide both diesel-like efficiency and very low emissions of nitrogen oxide (NOx) and particulate matter(PM). However, several technical issues still must be resolved before HCCI can see application. Among these, steep pressure-rise rate which leads to narrow operating range of HCCI engine continues to be a major issue. This work investigates the combination of two methods to mitigate the excessive pressure-rise rates at high power output, namely fuel stratification and Cooled exhaust-gas recirculation (Cooled EGR), after identifying the each effects to pressure-rise rate. When applying the fuel stratification to simulation, total fuelling width of 0.15 at BDC is set as a equivalent ratio difference based on the previous research. In order to simulate the effects of cooled EGR, $CO_2$ mole fraction in pre-mixture is changed ranging from 0 to 30%. DME which has a characteristic of two-stage ignition is used as a fuel.

Potential of Thermal Stratification and Partial Fuel Stratification for Reducing Pressure Rise Rate in HCCI Engines (HCCI 기관에 있어서의 층상 흡기를 통한 압력 상승률 저감에 대한 단위반응 수치 해석)

  • Lim, Ock-Taeck
    • Journal of the Korean Institute of Gas
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    • v.13 no.6
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    • pp.21-28
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    • 2009
  • The purpose of this study is to gain a better understanding of the effects of thermal stratification and partial fuel stratification on reducing the pressure-rise rate and emission in HCCI combustion. The engine is fueled with Di-Methyl Ether(DME) which has unique 2-stage heat release. Computational work is conducted with multi-zones model and detailed chemical reaction scheme. Calculation result shows that wider thermal stratification and partial fuel stratification prolong combustion duration and reduce pressure rise rate. But too wide partial fuel stratification increases CO and NOx concentration in exhaust gas, and decreases combustion efficiency.

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The Integration of Adaptive Elements into High-Rise Structures

  • Weidner, Stefanie;Steffen, Simon;Sobek, Werner
    • International Journal of High-Rise Buildings
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    • v.8 no.2
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    • pp.95-100
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    • 2019
  • Whilst most research focuses on the reduction of operative energy use in buildings, the aspect of which (and how many) materials are used is often neglected and poorly explored. However, considering the continuous growth of the global population and the limited availability of resources, it is clear that focusing on operative energy alone is too short-sighted. The tasks lying ahead for architects and engineers cannot be accomplished with conventional methods of construction. With a share of 50-60% of global resource consumption, the building industry has a decisive impact on our environment. If business as usual continues, resources will be significantly depleted in a matter of decades. Therefore, researchers of the University of Stuttgart are investigating the concept of adaptivity as a promising method for saving resources in the built environment. The term adaptivity in the context of building structures was first introduced by Werner Sobek. It describes a method where sensors, actuators and control units are implemented in systems or facades in order to oppose physical impacts in an ideal way. The applicability of this method will be verified on an experimental high-rise building at the University campus in Stuttgart. Thus, this paper describes this innovative research project and depicts the concept of adaptivity in high-rise structures. Furthermore, it gives an overview of potential actuation concepts and the interdisciplinary challenges behind them.

A Study on a Risk Assessment Method and Building Simulation for the Development of a Korean Integrated Disaster Evaluation Simulator (K-IDES) for High-rise Buildings

  • Kim, Tae-Young;Han, Gi-Sung;Kang, Boo-Seong;Lee, Kyung-Hoon
    • Architectural research
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    • v.22 no.4
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    • pp.105-112
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    • 2020
  • The purpose of this study is to establish a method for assessing a building's risk against disaster, tentatively named the Korean integrated disaster evaluation simulator (K-IDES). Based on previous studies, FEMA's risk management series and FEMA IRVS are selected as case studies for developing a frame work of K-IDES, through the comparative analysis of domestic building design guides, codes, and special acts related to disasters, in order to develop a risk assessment methodology for quantitative results. The assessment method consists of a classification system and calculating risk, and a simulation applying the developed checklist in K-IDES to similar types of high-rise buildings will be conducted to validate its accuracy. The final goal is to systemize an integrated risk management in a high-rise building against disasters for the purpose of recognizing vulnerable areas from the beginning of the design process and reinforcing it from potential threats after construction.

A Study on Flooding Prevention Scheme due to Sea Level Rise at Young-do Coast in Busan (부산 영도 해안의 해수면 상승에 따른 침수대책 연구)

  • Hong, Sung-Ki;Kang, Yong-Hoon;Lee, Han-Seok
    • Journal of Navigation and Port Research
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    • v.37 no.4
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    • pp.409-418
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    • 2013
  • On the assumption of the rise of sea level, the inundation vulnerabilities on coastal areas of Korea are evaluated in different ways. The propose of this study is to find out the influences of sea level rise caused by global warming at Young-do coastal area, and to suggest the prevention schemes against the flooding damage caused by the sea level rise. The potential rates of sea level rise are assumed and with these rates the inundation vulnerabilities are simulated using CAD program. With the virtual maps, as the results of the previous CAD simulation, this study attempts to suggest the flood prevention schemes for each sector of damage-expected coastal area.

Model reduction techniques for high-rise buildings and its reduced-order controller with an improved BT method

  • Chen, Chao-Jun;Teng, Jun;Li, Zuo-Hua;Wu, Qing-Gui;Lin, Bei-Chun
    • Structural Engineering and Mechanics
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    • v.78 no.3
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    • pp.305-317
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    • 2021
  • An AMD control system is usually built based on the original model of a target building. As a result, the fact leads a large calculation workload exists. Therefore, the orders of a structural model should be reduced appropriately. Among various model-reduction methods, a suitable reduced-order model is important to high-rise buildings. Meanwhile, a partial structural information is discarded directly in the model-reduction process, which leads to the accuracy reduction of its controller design. In this paper, an optimal technique is selected through comparing several common model-reduction methods. Then, considering the dynamic characteristics of a high-rise building, an improved balanced truncation (BT) method is proposed for establishing its reduced-order model. The abandoned structural information, including natural frequencies, damping ratios and modal information of the original model, is reconsidered. Based on the improved reduced-order model, a new reduced-order controller is designed by a regional pole-placement method. A high-rise building with an AMD system is regarded as an example, in which the energy distribution, the control effects and the control parameters are used as the indexes to analyze the performance of the improved reduced-order controller. To verify its effectiveness, the proposed methodology is also applied to a four-storey experimental frame. The results demonstrate that the new controller has a stable control performance and a relatively short calculation time, which provides good potential for structural vibration control of high-rise buildings.