• 제목/요약/키워드: Resilience engineering

검색결과 351건 처리시간 0.023초

회복탄력성을 고려한 기상 시나리오별 가뭄 용수 공급방안: 나주호를 중심으로 (Water Supply Alternatives for Drought by Weather Scenarios Considering Resilience: Focusing on Naju Reservoir)

  • 박진현;고재한;조영준;정경훈;성무홍;정형모;박현규;유승환;윤광식
    • 한국농공학회논문집
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    • 제60권5호
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    • pp.115-124
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    • 2018
  • Resilience has been widely used in various fields including design and operation of infrastructures. The resilient infrastructures not only reduce the damage scale of various disasters but also reduce the time and cost required for restoration. However, resilience rarely applied to promote efficient management of agricultural infrastructures. Recently, drought is an aggravating disaster by climate change and need countermeasures. Therefore, we tried to demonstrate evaluating measures in case of drought under consideration of resilience. This study applied the robustness-cost index (RCI) to evaluate alternative solution of the supply problem of a large agricultural reservoir under drought conditions. Four structural alternatives were selected to estimate the robustness index (RI) and the cost index (CI) to obtain the RCI values. Structural alternatives are classified into temporary measures and permanent measures. Temporary measures include the development of a tube wells and the installation of the portable pump, while the permanent measures include the installation of a pumping stations and the pumping water to the reservoir (Yeongsan River-Naju reservoir). RCI values were higher in permanent measures than those of temporary measures. Initial storage of the reservoir also affected RCI values of the drought measures. Permanent measures installation and management of early stage of the reservoir storage shortage was identified as the most resilient system.

Seismic resilience evaluation of RC-MRFs equipped with passive damping devices

  • Kamaludin, Puteri Nihal Che;Kassem, Moustafa Moufid;Farsangi, Ehsan Noroozinejad;Nazri, Fadzli Mohamed;Yamaguchi, Eiki
    • Earthquakes and Structures
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    • 제18권3호
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    • pp.391-405
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    • 2020
  • The use of passive energy dissipation devices has been widely used in the construction industry to minimize the probability of damage occurred under intense ground motion. In this study, collapse margin ratio (CMR) and fragility curves are the main parameters in the assessment to characterize the collapse safety of the structures. The assessment is done on three types of RC frame structures, incorporating three types of dampers, viscoelastic, friction, and BRB dampers. The Incremental dynamic analyses (IDA) were performed by simulating an array of 20 strong ground motion (SGM) records considering both far-field and near-field seismic scenarios that were followed by fragility curves. With respect to far-field ground motion records, the CMR values of the selected frames indicate to be higher and reachable to safety margin more than those under near-field ground motion records that introduce a high devastating impact on the structures compared to far-field excitations. This implies that the near field impact affects the ground movements at the site by attenuation the direction and causing high-frequency filtration. Besides that, the results show that the viscoelastic damper gives better performance for the structures in terms of reducing the damages compared to the other energy dissipation devices during earthquakes.

그래프 기반 바이너리 구조 비교 기법의 강인성 개선 (Improving Resilience in Graph-based Structure Comparison for Binary Objects)

  • 장준혁;조유근;홍지만
    • 한국정보과학회:학술대회논문집
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    • 한국정보과학회 2012년도 한국컴퓨터종합학술대회논문집 Vol.39 No.1(A)
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    • pp.104-106
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    • 2012
  • 소프트웨어 버스마크 (Software Birthmark)는 프로그램 실행 파일로부터 프로그램의 고유한 정보를 추출하는 기법이다. 프로그램의 도용을 판별하기 위해 바이너리로부터 버스마크를 추출하여 원본 프로그램과의 유사도를 측정하거나 악성 코드 탐지에 사용된다. 본 논문에서는 그래프 기반 바이너리 구조 매칭기법을 기반으로 한 버스마크를 제안한다. 제안 기법은 원본 프로그램과 대상 프로그램 사이에서 함수와 함수, 기본 블록과 기본 블록의 매칭 방법을 개선함으로써, 기존 기법에 비해 강인성(Resilience)이 향상된 버스마크를 추출한다.

음의 각을 가지는 허니컴 스포크를 사용한 비 공압타이어의 접지압 분포 (Contact Pressure of Non-Pneumatic Tires with Auxetic Honeycomb Spoke)

  • 김광원;김두만
    • 항공우주시스템공학회지
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    • 제4권2호
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    • pp.1-9
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    • 2010
  • An airless tire has advantages over the conventional pneumatic tire in terms of flat proof and maintenance free. According to the recently disclosed inventions on the airless tire, non-pneumatic tire (NPT) consists of the flexible polygon spokes. Considering the NPT structure, the spokes undergo the tension-compression cyclic loading while the tire rolls. Therefore the spokes of NPT are required to have both stiffness and resilience under the cyclic tensile-compressible loading. In general, if a material has a high stiffness, it shows a low elastic strain limit. In this paper, using the auxetic honeycomb structure with negative poissons's ratio, the spokes of NPT tire are designed to have both stiffness and resilience. Finite element based numerical simulation of the contact pressure of a NPT is carried out with ABAQUS.

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Effects of Phosphorus and Iron on the Phytotoxicity of Lettuce (Lactuca sativa L.) in Arsenic-contaminated Soil

  • Kim, Min-Suk;Min, Hyun-Gi;Kim, Jeong-Gyu
    • Ecology and Resilient Infrastructure
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    • 제5권1호
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    • pp.1-10
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    • 2018
  • We examined the effect of simultaneous application of phosphorus (P) and iron (Fe) on the phytotoxicity of lettuce in arsenic (As) contaminated soil using response surface methodology (RSM). To stabilize As and supply nutrient into soil, Fe and P were treated, respectively. Water soluble As and P was decreased by Fe application but increased by P application. Through phytotoxicity test, the result showed that only the addition of P affected lettuce root elongation even though both P and Fe were added. The correlation coefficients between root elongation and other indices indicated that the As content in the roots seemed to be the main reason that root growth was impeded. We could verify that the former result was not a passing phenomenon and Fe was necessarily needed to protect secondary pollution by exclusive usage of P fertilizer.

Mechanical properties of reinforced-concrete rocking columns based on damage resistance

  • Zhu, Chunyang;Cui, Yanqing;Sun, Li;Du, Shiwei;Wang, Xinhui;Yu, Haochuan
    • Structural Engineering and Mechanics
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    • 제80권6호
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    • pp.737-747
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    • 2021
  • The objective of seismic resilience is to maintain or rapidly restore the function of a building after an earthquake. An efficient tilt mechanism at the member level is crucial for the restoration of the main structure function; however, the damage resistance of the members should be the main focus. In this study, through a comparison with the classical Flamant theory of local loading in the elastic half-space, an elastomechanical solution for the axial-stress distribution of a reinforced-concrete (RC) rocking column was derived. Furthermore, assuming that the lateral displacement of the rocking column is determined by the contact surface rotation angle of the column end and bending and shear deformation of the column body, the load-lateral displacement mechanical model of the RC rocking column was established and validated through a comparison with finite-element simulation results. The axial-compression ratio and column-end strength were analyzed, and the results indicated that on the premise of column damage resistance, simply increasing the axial-compression ratio increases the lateral loading capacity of the column but is ineffective for improving the lateral-displacement capacity. The lateral loading and displacement of the column are significantly improved as the strength of the column end material increases. Therefore, it is feasible to improve the working performance of RC rocking columns via local reinforcement of the column end.

Ecological responses of natural and planted forests to thinning in southeastern Korea: a chronosequence study

  • Cho, Yong-Chan;Pee, Jung-Hun;Kim, Gyeong-Soon;Koo, Bon-Yoel;Cho, Hyun-Je;Lee, Chang-Seok
    • Journal of Ecology and Environment
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    • 제34권4호
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    • pp.347-355
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    • 2011
  • Effects of forest thinning on community level properties have not been understood yet in Korea. We investigated regeneration patterns and trajectories after a disturbance by applying a chronosequence approach. Light availability, litter and woody debris cover, and species composition were determined for twenty 50 m line-transect samples representing a disturbance duration gradient (within 11 years). Environmental factors such as light availability and coverage of woody debris and litter changed abruptly after thinning and then returned to the pre-disturbance state. Although species richness was gained at shrub and ground layer in a limited way in both forests, cover of various functional types revealed diversity in their responses. Notably, Alnus firma stands exhibited a larger increment of cover in woody plants. Ordination analysis revealed different regeneration trajectories between natural and planted stands. Based on ordination analysis, rehabilitated stands showed movement to alternative states compared with natural ones, reflecting lower resilience to perturbation (i.e., lower stability). Our results suggest that community resilience to artificial thinning depends on properties of the dominant species. But to get more explanatory ecological information, longer-term static observations are required.

키토산 가교처리된 면직물의 태 변화에 관한 연구 - 에피클로로히드린과 키토산 농도의 영향- (A study on the Change of Hand of Chitosan Crosslinked Cotton Fabrics - Effect of Concentration of Epichlorohydrin and Chitosan -)

  • 김민지;박정우;이신희
    • 한국의류산업학회지
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    • 제6권5호
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    • pp.660-666
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    • 2004
  • This article describes the change of hand value of chitosan crosslinked cotton fabrics. The chitosan crosslinked cotton fabrics were manufactured by mercerizing process using epichlorohydrin(ECH) as crosslinkins agent, 2% aqueous acetic acid as a solvent of chitosan and ECH, and 20% aqueous sodium hydroxide as a mercerizing agent and crosslinking catalyst. Cotton fabrics were dipped in the mixed solution of chitosan and ECH, picked up by mangle, mercerized and crosslinked in NaOH solution, and finally wash and dry. Mechanical and physical properties of the chitosan crosslinked fabric were investigated using Kawabata Evaluation System(KES) and other instruments. Tensile energy and tensile strain were decreased with the increase of the concentration of chitosan. Tensile resilience, compression resilience bending rigidity, bending hysteresis, shear stiffness, shear hysteresis, coefficient of friction, geometrical roughness, compression linearity, compressional energy, and thickness were increased with the increase of the concentration of chitosan. On the other hand, bending rigidity, bending hysteresis, coefficient of friction, geometrical roughness, compressional resilience, and thickness were increased with the increase of the concentration of crosslinking agent(epichlorohydrin).

마음빼기명상 프로그램이 119 구급대원의 외상 후 성장과 회복탄력성에 미치는 효과 (Effects of Mind Subtraction Meditation Program on Post-traumatic Growth)

  • 이인수;전민영;유양경
    • 한국화재소방학회논문지
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    • 제32권5호
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    • pp.95-104
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    • 2018
  • 119 구급대원은 외상성 사건에 지속적으로 노출되며 이로 인해 다양한 사회심리적 문제와 삶의 질 저하를 경험할 위험이 있다. 이에 본 연구에서는 마음빼기명상 프로그램이 119 구급대원의 외상 후 성장과 회복탄력성에 미치는 효과를 확인하였다. $201^*$년 A소방본부 구급대원 26명을 연구대상으로, 2박 3일간 단기집중 마음빼기명상 프로그램을 적용하기 전과 명상 완료 후에 외상 후 성장과 회복탄력성 설문지를 이용하여 대상자의 상태를 측정하였다. 연구 결과 마음빼기명상 프로그램은 119 구급대원의 외상 후 성장을 $2.85({\pm}.67)$점에서 $3.60({\pm}.72)$점으로 유의하게 증가시켰고, 회복탄력성은 $2.45({\pm}.39)$점에서 $2.83({\pm}.48)$점으로 유의하게 증가시켰다. 결론적으로 마음빼기명상 프로그램은 119 구급대원의 외상 후 성장과 회복탄력성을 향상시키는 효과가 있었으므로, 본 연구에 적용한 마음빼기명상은 119 구급대원의 정신건강관리 프로그램으로 제안될 수 있을 것이다.

PTT BCF카펫과 나일론 BCF카펫의 압축특성(壓縮特性)에 관(關)한 연구(硏究) (Compressional Properties of PTT BCF and Nylon BCF Carpets)

  • 윤명희;김종준;전동원
    • 패션비즈니스
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    • 제8권5호
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    • pp.115-124
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    • 2004
  • PTT(polytrimethylene terephthalate) is a thermoplastic that can be melt-spun into fibers and has extensive applications in carpets, textiles and apparel, engineering thermoplastics, nonwovens, and films or sheets. This polymer combines the good properties of nylon and polyester. Compared with other synthetic fibers such as nylon and acrylic, the PTT fibers feel softer, dye easier with vibrant colors, stretch and recover better. Moreover, the PTT fibers for carpets resist most stainings, clean better, and dry faster. The PTT was first patented in 1941, but it was not until the 1990's, when Shell Chemicals developed the practical method of producing PDO, the raw material for PTT. Many studies have been done including the retention of carpet texture using an image analysis technique, or compressional resilience of the carpet for long term use. In this study, PTT and nylon BCF carpets were compared in terms of the compressional properties including the resilience, using one of the KES system for repetitive measurements. The compression resilience(RC) values of the PTT BCF carpets far exceed those of nylon 6 BCF carpets. The RC values of the PTT BCF carpet(cut) specimens are $42{\sim}45%$ for 5 successive compression deformations, while those of the nylon BCF carpet specimens(cut) are $26{\sim}28%$. There is also a similar trend in the RC values for the other type of carpet which is the loop type. This resilience is one of the important factors of carpet usage evaluation.