• 제목/요약/키워드: Assessment of deterioration

검색결과 332건 처리시간 0.032초

Assessment of riparian buffers for reducing pollution according to land-cover pattern using RS and GIS

  • Ha, Sung-Ryong;Lee, Seung-Chul;Ko, Chang-Hwan;Jo, Yun-Won
    • 대한원격탐사학회지
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    • 제22권5호
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    • pp.445-449
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    • 2006
  • Diffuse pollution has been considering as a major source of the quality deterioration of water resources. The establishment of riparian vegetation strips or buffers along those areas of water bodies is used to reduce the threat of diffuse pollution. Remote sensing offers a means by which critical areas could be identified, so that subsequent action toward the establishment of riparian zones can be taken. On the behalf of KOMPSAT-2 satellite imagery as a high resolution spatial data, Landsat TM satellite data are used to aquire the land cover for the riparian buffers studied. This investigation aims to assess the riparian buffers established on the upper Geum river as a pollution mitigation. Through comparing the delineation of riparian buffer zones developed with the existing zones established by the government, we can find the critical distortion points of the existing riparian buffer zone.

전력선통신 기반 A/V 신호 송수신기 설계 및 특성분석

  • 김지형;김용갑
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2009년도 추계학술대회 논문집
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    • pp.285-285
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    • 2009
  • Due to a development of a modem technology as Power Line Communication(PLC) over 200 Mbps, the high-speed multi-media data trasmission could be currently possible. In This paper we develop a high quality media transmitter-receiver based on merging the HomePlug AV, which is 200 Mbps class PLC technology and HDMI Interface technology. Smart Live 6 software were used for the assessment of audio property. As the result of measurement of the HD class images by capturing from the receiver of the PLC, the quality of images couldn't be confirm any deterioration, which has compared with original reflections. In case of audio part as the result of confirmation of the Phase, Magnitude, it has been confirmed that over 90% of nomal transmition and receiving of acoustic signal.

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화재피해를 입은 콘크리트 구조물의 유지관리방안 (The Maintenance Methods of Concrete Deterioration caused by Fire Attack)

  • 권영진;윤웅기;구인혁
    • 한국건축시공학회:학술대회논문집
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    • 한국건축시공학회 2015년도 춘계 학술논문 발표대회
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    • pp.236-237
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    • 2015
  • Concrete is the one of the most widely used in every country as a structural materials. On the other hand, a lot of fire incident has been occurred all over the world. But maintenance methods such as inspection and diagnostic methods, design methods, quality control methods for the purpose of improving the performance of concrete structures damaged by fire has made in its own way. Therefore, the purpose of this proposal of new working item is is to ensure the safety of the concrete structures damaged by fire in the field of assessment of damage, design, repair methods and so on through the International Organization for Standardization.

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폐유리를 혼입한 콘크리트의 황산마그네슘 저항성에 관한 연구 (Magnesium Sulfate Resistance of Concrete Containing Waste Glass)

  • 김영수;정유진;이동운
    • 한국건축시공학회지
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    • 제9권3호
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    • pp.109-116
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    • 2009
  • The magnesium sulfate solution digestion test carried out for resistance of concrete containing waste glass powder on magnesium sulfate attack. Moreover, it yielded S.D.F index was used for the criteria of quantitative assessment to the resistance of magnesium sulfate for the purpose of evaluation of chemical deterioration on concrete. Furthermore, to evaluate for micro-cracks within concrete and external corrosion, the weight variation of specimens and the dynamic elasticity were compared and analyzed and also the applicability was examined using the analysis of product of hydration through out observing external deformation and micro-structural deformation.

대류.복사 연성시뮬레이션을 통한 옥외 온열환경 평가 기법 (Study on assessment of outdoor thermal environment with coupled simulation of convection and radiation)

  • 류민경;임종연;황효근;송두삼
    • 대한설비공학회:학술대회논문집
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    • 대한설비공학회 2009년도 하계학술발표대회 논문집
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    • pp.565-572
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    • 2009
  • Deterioration of the outdoor thermal environment in urban areas such as heat island has become worse due to urbanization and overpopulation, etc. In this study, a new method which is coupled simulation of convection and radiation to evaluate outdoor thermal environment in urban area will be proposed. Because the solar radiation affects on outdoor thermal environment massively, therefore the radiation calculation is very important in outdoor thermal environment prediction. The coupled simulation proposed in this study can assess the outdoor thermal environment with accurate.

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Reliability assessment of concrete bridges subject to corrosion-induced cracks during life cycle using artificial neural networks

  • Firouzi, Afshin;Rahai, Alireza
    • Computers and Concrete
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    • 제12권1호
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    • pp.91-107
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    • 2013
  • Corrosion of RC bridge decks eventually leads to delamination, severe cracking and spalling of the concrete cover. This is a prevalent deterioration mechanism and demands for the most costly repair interventions during the service life of bridges worldwide. On the other hand, decisions for repairs are usually made whenever the extent of a limit crack width, reported in routine visual inspections, exceeds an acceptable threshold level. In this paper, while random fields are applied to account for spatial variation of governing parameters of the corrosion process, an analytical model is used to simulate the corrosion induced crack width. However when dealing with random fields, the Monte Carlo simulation is apparently an inefficient and time consuming method, hence the utility of neural networks as a surrogate in simulation is investigated and found very promising. The proposed method can be regarded as an invaluable tool in decision making concerning maintenance of bridges.

인공강우를 이용한 축종별 축분퇴비침출수의 수질특성 조사 (Assessment of Leachate Characteristics of Manure Compost under Rainfall Simulation)

  • 홍성구;김진태
    • 농촌계획
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    • 제7권2호
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    • pp.65-73
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    • 2001
  • Animal manure and manure compost produced from livestock farms are widely applied in crop lands. Leachate and runoff water from them are presumed to be one of the major sources of water quality deterioration in rural streams. Laboratory experiments were conducted to investigate water quality characteristics and loading of leachate obtained under rainfall simulation. Manure composts for the experiments were collected from beef cattle farms, dairy farms, and pig farms. Water quality parameters include SS, COD, TN, and TP. Most parameters of leachate from pig manure compost was higher than others. Both TN and TP concentrations were reflecting the composition of manure itself. It is recommended, therefore that the leachate from the manure composts should be controlled not to be discharged into streams.

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제한된 출력자료를 이용한 구조물의 손상도 추정 (Identification of Structural Damage with Limited Output Measurement)

  • 최영민;조효남;황윤국;김정호
    • 한국전산구조공학회:학술대회논문집
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    • 한국전산구조공학회 2001년도 가을 학술발표회 논문집
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    • pp.101-108
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    • 2001
  • In the previous study, an improved QRD (QR Decomposition)-ILS(Iterative Least-Squares) method is proposed to estimate the structural parameters at the element level using response data alone without using any information of excitation measurements for the assessment of local damages and deterioration in complex and large structural systems. But for a complex and large structural system, where response measurement at every dynamic degree of freedom(DDOF) is not possible, the absence of some observation points of responses and its effect on the proposed SI method must be studied In the paper, a QRD-ILS technique that utilizes the known intact stiffness information estimated based on the visual inspection, field measurements and/or NDT tests is proposed to identify local damages of fracture critical members using measured responses only at limited DDOFs. A numerical example is used to illustrate the application of this technique. The results indicate that the proposed SI technique is very simple but efficient, since no input information are required with only limited observations.

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콘크리트 층간비저항에 의한 철근의 부식환경 평가에 관한 연구 (A Study on the Evaluation of the Corrosive Environment of Reinforcement Bar by Concrete Layer Resistivity)

  • 임영철
    • 한국건축시공학회:학술대회논문집
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    • 한국건축시공학회 2012년도 추계 학술논문 발표대회
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    • pp.43-44
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    • 2012
  • Deterioration factors such as CO2 and chloride ions cause steel corrosion in RC structures. The diffusion of these factors depends on the water content in concrete. To examine the moisture condition of concrete, this research considers the availability of the steel effect ratio, which is calculated by Resistivity Estimation Model (REM). It is concluded that the steel effect ratio is expected to be available as a quantitative evaluation method in the assessment of concrete layer resistivity.

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초기재령 콘크리트의 세공구조 형성 및 발영특성에 관한 미시역학적 모델 (Micromechanics based Models for Pore-Sructure Formation and Hydration Heat in Early-Age Concrete)

  • 조호진;박상순;송하원;변근주
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 1999년도 봄 학술발표회 논문집(I)
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    • pp.123-128
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    • 1999
  • Recently, as a performance based design concept is introduced, assurance of expected performances on serviceability and safety in the whole span of life is exactly requested. So, quantitative assessments about durability related properties of concrete in early-age long term are come to necessary, Especially in early age, deterioration which affects long-term durability performance can be occurred by hydration heat and shrinkage, so development of reasonable hydration heat model which can simulate early age behavior is necessary. The micor-pore structure formation property also affects shrinkage behavior in early age and carbonations and chloride ion penetration characteristic in long term, So, for the quantitative assessment on durability performance of concrete, modelings of early age concrete based on hydration process and micor-pore structure formation characteristics are important. In this paper, a micromechanics based hydration heat evolution model is adopted and a quantitative model which can simulate micro-pore structure development is also verified with experimental results. The models can be used effectively to simulate the early-age behavior of concrete composed of different mix proportions.

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