• Title/Summary/Keyword: fragility functions

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Earthquake Loss Estimation Including Regional Characteristics (지역특성을 반영한 지진손실평가)

  • Kim, Joon-Hyung;Hong, Yun-Su;Yu, Eunjong
    • Journal of the Earthquake Engineering Society of Korea
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    • v.27 no.6
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    • pp.311-320
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    • 2023
  • When an earthquake occurs, the severity of damage is determined by natural factors such as the magnitude of the earthquake, the epicenter distance, soil properties, and type of the structures in the affected area, as well as the socio-economic factors such as the population, disaster prevention measures, and economic power of the community. This study evaluated the direct economic loss due to building damage and the community's recovery ability. Building damage was estimated using fragility functions due to the design earthquake by the seismic design code. The usage of the building was determined from the information in the building registrar. Direct economic loss was evaluated using the standard unit price and estimated building damage. The standard unit price was obtained from the Korean Real Estate Board. The community's recovery capacity was calculated using nine indicators selected from regional statistical data. After appropriate normalization and factor analysis, the recovery ability score was calculated through relative evaluation with neighboring cities.

Nitric Oxide Exerts Different Functions on Porcine Oocytes Cultured in Different Models, Which is Affected by Beta-mercaptoethanol

  • Tao, Yong;Xia, Guoliang;Bo, Shumin;Zhou, Bo;Zhang, Meijia;Wang, Fenghao
    • Asian-Australasian Journal of Animal Sciences
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    • v.17 no.3
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    • pp.317-324
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    • 2004
  • The present study was conducted to investigate the involvement of nitric oxide (NO) in cumulus expansion, oocyte mortality and meiotic maturation of porcine cumulus enclosed oocytes (CEOs) cultured in two different models when gonadotropins, including follicle-stimulating hormone (FSH) and human chorionic gonadotropin (hCG) were presented or not. And the interaction between NO and $\beta$-mercaptoethanol ($\beta$-ME), a free radical scavenger was also investigated. Two models refer to spontaneous maturation model and hypoxanthine (HX) medium model. All the 3,433 eligible CEOs were incubated at $39^{\circ}C$ and the cumulus expansion, oocyte morphology and nuclear phase were evaluated 44 h after incubation. (1) In spontaneous maturation model, NO stimulates the cumulus expansion and $\beta$-ME delayed it. NO doesn't affect the oocyte meiotic resumption but inhibits the oocytes to develop to metaphase II. (2) In HX medium model, NO or $\beta$-ME doesn't affect the expansion in the absence of gonadotropins, but in the presence of gonadotropins, NO or $\beta$-ME inhibits the expansion. In the presence of gonadotropins, NO inhibits the oocyte meiotic resumption and it especially inhibits the oocyte to develop to metaphase II, and $\beta$-ME reverses such inhibitory effects. The cooperation of gonadotropins and $\beta$-ME stimulates the meiotic resumption and especially, promotes the CEOs to develop to metaphase II in both models. Moreover, HX might contribute to the fragility of oocyte zona pellucida and gonadotropins, nitric oxide and $\beta$-ME could alleviate it separately, and cooperatively. It is concluded that NO exerts different functions in two models and $\beta$-ME affected the functions of NO in different models.

Robust and Non-fragile $H^{\infty}$ Controller Design for Tracking Servo of Blu-ray disc Drive System (Blu-ray 디스크 드라이브 시스템 트래킹 서보시스템에 대한 견실비약성 $H^{\infty}$ 상태궤환 제어기 설계)

  • Lee, Hyung-Ho;Kim, Joon-Ki;Kim, Woon-Ki;Jo, Sang-Woo;Park, Hong-Bae
    • Journal of the Institute of Electronics Engineers of Korea SC
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    • v.45 no.3
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    • pp.32-41
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    • 2008
  • In this paper, we describe the synthesis of robust and non-fragile $H^{\infty}$ state feedback controllers for linear systems with affine parameter uncertain tracking servo system of blu-ray disc drive, as well as static state feedback controller with polytopic uncertainty Similarity any other control system, the objective of the track-following system design for optical disc drives is to construct the system with better performance and robustness against modeling uncertainties and various disturbances. Also, the obtained condition can be rewritten as parameterized linear matrix inequalities(PLMIs), that is, LMIs whose coefficients are functions of a parameter confined to a compact set. We show that the resulting controller guarantees the asymptotic stability and disturbance attenuation of the closed loop system in spite of controller gain variations within a resulted polytopic region.

Quantifying the seismic resilience of two tall buildings designed using Chinese and US Codes

  • Tian, Yuan;Lu, Xiao;Lu, Xinzheng;Li, Mengke;Guan, Hong
    • Earthquakes and Structures
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    • v.11 no.6
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    • pp.925-942
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    • 2016
  • With ongoing development of earthquake engineering research and the lessons learnt from a series of strong earthquakes, the seismic design concept of "resilience" has received much attention. Resilience describes the capability of a structure or a city to recover rapidly after earthquakes or other disasters. As one of the main features of urban constructions, tall buildings have greater impact on the sustainability and resilience of major cities. Therefore, it is important and timely to quantify their seismic resilience. In this work, a quantitative comparison of the seismic resilience of two tall buildings designed according to the Chinese and US seismic design codes was conducted. The prototype building, originally designed according to the US code as part of the Tall Building Initiative (TBI) Project, was redesigned in this work according to the Chinese codes under the same design conditions. Two refined nonlinear finite element (FE) models were established for both cases and their seismic responses were evaluated at different earthquake intensities, including the service level earthquake (SLE), the design-based earthquake (DBE) and the maximum considered earthquake (MCE). In addition, the collapse fragility functions of these two building models were established through incremental dynamic analysis (IDA). Based on the numerical results, the seismic resilience of both models was quantified and compared using the new-generation seismic performance assessment method proposed by FEMA P-58. The outcomes of this study indicate that the seismic resilience of the building according to the Chinese design is slightly better than that according to the US design. The conclusions drawn from this research are expected to guide further in-depth studies on improving the seismic resilience of tall buildings.

(Robust Non-fragile $H^\infty$ Controller Design for Parameter Uncertain Systems) (파라미터 불확실성 시스템에 대한 견실 비약성 $H^\infty$ 제어기 설계)

  • Jo, Sang-Hyeon;Kim, Gi-Tae;Park, Hong-Bae
    • Journal of the Institute of Electronics Engineers of Korea SC
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    • v.39 no.3
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    • pp.183-190
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    • 2002
  • This paper describes the synthesis of robust and non-fragile H$\infty$ state feedback controllers for linear varying systems with affine parameter uncertainties, and static state feedback controller with structured uncertainty. The sufficient condition of controller existence, the design method of robust and non-fragile H$\infty$ static state feedback controller, and the set of controllers which satisfies non-fragility are presented. The obtained condition can be rewritten as parameterized Linear Matrix Inequalities(PLMls), that is, LMIs whose coefficients are functions of a parameter confined to a compact set. However, in contrast to LMIs, PLMIs feasibility problems involve infinitely many LMIs hence are inherently difficult to solve numerically. Therefore PLMls are transformed into standard LMI problems using relaxation techniques relying on separated convexity concepts. We show that the resulting controller guarantees the asymptotic stability and disturbance attenuation of the closed loop system in spite of controller gain variations within a degree.

Decision Making of Seismic Performance Management for the Aged Road Facilities Based on Road-Network and Fragility Curve (취약도곡선을 이용한 도로망기반 노후도로시설물 내진성능관리 의사결정)

  • Kim, Dong-Joo;Choi, Ji-Hae
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.25 no.5
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    • pp.94-101
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    • 2021
  • According to the Facility Management System (FMS) operated by the Korea Authority of Land & Infrastructure Safety, it is expected that the number of aging facilities that have been in use for more than 30 years will increase rapidly to 13.9% in 2019 and 34.5% in 2929, and end up with a social problem. In addition, with the revision of "Common Application of Seismic Design Criteria" by the Ministry of Public Administration and Security in 2017, it is mandatory to re-evaluate all existing road facilities and if necessary seismic reinforcement should be done to minimize the magnitude of earthquake damage and perform normal road functions. The seismic performance management-decision support technology currently used in seismic performance management practice in Korea only determines the earthquake-resistance reinforcement priority based on the qualitative index value for the seismic performance of individual facilities. However with this practice, normal traffic functions cannot be guaranteed. A new seismic performance management decision support technology that can provide various judgment data required for decision making is needed to overcome these shortcomings and better perform seismic performance management from a road network perspective.