• Title/Summary/Keyword: Quantitative Estimation

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Shaking Table Test of Full Scale Parapet Models for the Evaluation of Intensities of Historical Earthquakes (성첩 모델의 진동대 실험과 역사지진의 세기 평가)

  • 김재관
    • Proceedings of the Earthquake Engineering Society of Korea Conference
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    • 2001.04a
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    • pp.461-467
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    • 2001
  • Shaking table tests were performed with full scale models of stone parapet on the ancient rampart. The objectives of these tests are to study the seismic behavior of the parapet and to obtain quantitative estimation of the intensities of historical earthquakes. Two test models were made based on the structure of the parapet remnant of a mountain fortress in Bukhan-San located in Seoul. Two types of infilling material are considered. The responses to models were tested subjected to three kinds of input motion.

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Stress Histogram Analysis of Steel Plate Girder Railway Bridge due to Service Load Histories (실동하중에 의한 강판형철도교의 응력빈도해석)

  • Hwang, In-Gu;Kim, Yeon-Tae
    • Proceedings of the KSR Conference
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    • 2004.10a
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    • pp.928-933
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    • 2004
  • Despite the number of steel bridges being under in service more than 50 years reaches about 50$\%$ in present, the quantitative estimation in maintenance on steel railway bridges is not possible because a ton of the field data in the bridges have not been plentifully accumulated. Therefore, a series of field tests on the steel plate girder bridge, the typical types of steel railway bridges, are executed, and the stress characteristics of main members in steel plate girder railway bridges are quantitatively estimated in this study.

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An analysis of learning effect of finger's reaction time for middle and old aged

  • 서승록;이상도
    • Journal of the Ergonomics Society of Korea
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    • v.11 no.2
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    • pp.47-56
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    • 1992
  • In this paper, a mathematical model of learning curve is proposed to study the fi- nger's reaction time. The model is a logarithmic linear type which represents a lear- ning curve appropriately, and parameters are estimated by the linear. The learning coefficient and percentage of a reaction time can easily computed in the mathematical model. This quantitative approach provieds an important information to be used fot the working capqbility qualification of re-employment as well as the adaptability estimation of aged workers.

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Application of PIV to Fluid-Machinery Studies (유체기계연구에서의 PIV의 적용)

  • Lee, Y. H.
    • 유체기계공업학회:학술대회논문집
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    • 1997.02a
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    • pp.188-195
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    • 1997
  • The application of PIV to the studies of fluid-machines, especially focused on turbo-machinery is reviewed by scrutinizing the previous investigation. Owing to the inevitable high-speed analysis of turbo-machinery consisting of rotating impellers, the importance of optical setups to cope with illumination problem is frequently mentioned as main ingredient affecting the PIV performance. And the acquisition of the relative velocity and absolute velocity is determined mainly by the optical recording conditions. A few studies cast satisfactory extension of the PIV data to quantitative pressure estimation and related noise assessment.

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The Application of Safety Impact Assessment to Tunnel Construction (터널공사에서의 안전영향평가의 적용)

  • Kim, Byung-Sik;Choi, Bong-Joon;Seo, Jong-Won
    • 한국방재학회:학술대회논문집
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    • 2008.02a
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    • pp.545-548
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    • 2008
  • In this study, the concept of safety impact assessment to achieve 'Design-for-Safety' in design phase is introduced. For this purpose, safety impact assessment model was devised and a methodology using the risk-based safety impact assessment approach for NATM of tunnel projects is suggested. The suggested methodology includes safety information survey, classification of safety impact factors caused by design and construction, and quantitative estimation of magnitude and frequency of safety impact factors. A real-world case study on the safety impact assessment of a tunnel construction project is also provided in the paper.

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The analysis on learning effect of reaction time to the stimulus (자극에 의한 반응시간의 학습효과에 관한 연구)

  • S.L.Seung;Lee, S.D.
    • Proceedings of the ESK Conference
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    • 1992.10a
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    • pp.113-120
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    • 1992
  • In this paper, a mathematical model of learning curve is proposed to study the finger's reaction time. The model is a logarithmic linear type which represents a learning curve appropriately, and parameters are estimated by the linear. The learning coefficient and percentage of a reaction time can be easily computed in the mathematical model. This quantitative approach provides an important information to be used for the working capability qualification for re-employment as well as for the adaptability estimation of aged workers.

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Risk Assessment for Noncarcinogenic Chemical Effects

  • Kodell Ralph L.
    • 대한예방의학회:학술대회논문집
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    • 1994.02a
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    • pp.412-415
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    • 1994
  • The fundamental assumption that thresholds exist for noncarcinogenic toxic effects of chemicals is reviewed; this assumption forms the basis for the no-observed-effect level/ safety-factor (NOEL/SF) approach to risk assessment for such effects. The origin and evolution of the NOEL/SF approach are traced, and its limitations are discussed. The recently proposed use of dose-response modeling to estimate a benchmark dose as a replacement for the NOEL is explained. The possibility of expanding dose-response modeling of non carcinogenic effects to include the estimation of assumed thresholds is discussed. A new method for conversion of quantitative toxic responses to a probability scale for risk assessment via dose-response modeling is outlined.

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Estimation of Safety in Railway Tunnel by Using Quantitative Risk Assessment (QRA를 이용한 철도터널 방재 안전성 평가)

  • Kim, Do-Sik;Kim, Do-Hyung;Kim, Woo-Sung;Lee, Du-Hwa;Lee, Ho-Seok
    • Tunnel and Underground Space
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    • v.16 no.5 s.64
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    • pp.357-367
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    • 2006
  • Recently, as the construction of new railway and the relocation of existing line increase, tunnel structures grow longer. The railway fire accidents in long tunnel bring large damages of human life and disaster. The interest of safety in long tunnel have a growing and the safety standard of long tunnel is tightening. For that reason, at the planning of long tunnel, the optimum design of safety facility in long tunnel for minimizing the risks and satisfying the safety standard is needed. For the reasonable design of long railway tunnel considering high safety, qualitative estimation for tunnel safety is required. In this study, QRA (Quantitative Risk Assessment) technique is applied to design of long railway tunnel for assuring the safety function and estimating the risk of safety. The case study for safety design in long railway tunnel is tarried out to verifying the QRA technique for two railway tunnels. Thus, the inclined and vertical shaft for escape way and safety facilities in long tunnel are planned, and the risks of tunnel safety for each case are estimated quantitatively.

A Quantitative Approach to the influence on the South Korean Air Transportation System in the Event of Volcanic Ash Dispersal (화산재에 따른 국내항공교통의 영향에 대한 정량화 방안)

  • LEE, Jiseon;YOON, Yoonjin
    • Journal of Korean Society of Transportation
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    • v.34 no.4
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    • pp.318-329
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    • 2016
  • There has been a growing interest on the effect of volcanic eruption on the aviation safety, air travel and economy especially after the eruption of Eyjafjallajokull in Iceland. Since volcanic eruption is influential on a large geographic region, the effect usually extends to other neighboring countries. Korea also has an active volcano named Mountain Baekdu. Hence, the need to estimate in advance the quantitative impact of the potential eruption of Mt. Baekdu on South Korean air transportation system. However, previous studies with quantitative estimation were confined to the calculation of the direct economic loss from shut down of the airports, grounding of airlines, and trade deficits caused by the eruption. Therefore, this paper introduces a new approach to assess more accurate impact simultaneously considering volcanic ash dispersal and aviation routes. This approach is then applied to a virtual scenario to predict the damage to air traffic. With further development, this method can help estimate the damage in the air transportation industry in more accurate and faster ways. Prediction outcomes can also be utilized in setting up the emergency response plan for the air transportation industry and contribute to the creation of more proactive and predictive measures in the future.

Sensitivity of Input Parameters in the Spectral Wave Model

  • Park, Hyo-Bong
    • Journal of Ocean Engineering and Technology
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    • v.23 no.2
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    • pp.28-36
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    • 2009
  • Many researches have been done to define the physical parameters for the wave generation and transformation over a coastal region. However, most of these have been limited to the application of particular conditions, as they are generally too empirical. To yield more reasonable wave estimation using a spectral wave model, it is important to understand how they work for the wave estimation. This study involved a comprehensive sensitivity test against the spectral resolution and the physical source/sink terms of the spectral wave model using SWAN and TOMAWAC, which have the same physical background with several different empirical/theoretical formulations. The tests were conducted for the East Anglian coast, UK, which is characterized by a complex bathymetry due to several shoals and offshore sandbanks. For the quantitative and qualitative evaluation of the models' performance with different input conditions, the wave elements and spectrums predicted at representative sites the East Anglia coast were compared/analyzed. The spectral resolution had no significant effect on the model results, but the lowest resolution on the frequency and direction induced underestimations of the wave height and period. The bottom friction and depth-induced breaking terms produced relatively high variations in the wave prediction, depending on which formulation was applied. The terms for the quadruplet and whitecapping had little effect on the wave estimation, whereas the triads tended to predict shorter and higher waves by energy transferring to higher frequencies.