• Title/Summary/Keyword: probability index

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Development of Weigh Calculation Method for Pavement Roughness Index Considering Vehicle Wandering Distribution (원더링 분포를 고려한 도로포장 평탄성 지수의 가중치 산정기법 개발)

  • Lee, Jaehoon;Sohn, Ducksu;Park, Jejin;Cho, Yoonho
    • International Journal of Highway Engineering
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    • v.19 no.5
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    • pp.89-96
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    • 2017
  • PURPOSES: This study aims to develop a rational procedure for estimating the pavement roughness index considering vehicle wandering. METHODS : The location analysis of the passing vehicle in the lane was performed by approximately 1.2 million vehicles for verification of the wandering distribution. According to verification result, the distribution follows the normal distribution pattern. The probability density function was estimated using each lane's wandering distribution model. Then the procedure for applying a weighted value into the lane profile was conducted using this function. RESULTS : The modified index, MRIw, with consideration towards applying the wandering weighted value application was computed then compared with MRI. It was found that the Coefficient of Variation for distribution of lateral roughness index in the lane was high in the case of a large difference between each index (i.e., MRIw and MRI) observed. CONCLUSIONS : This result confirms that the new procedure with consideration of the weight factor can successfully improve the lane representative characteristics of the roughness index.

Impact Buckling Reliability Analysis of Stiffened Cylinder With Initial Geometric Imperfection (기하학적 초기형상결함을 갖는 보강 원통의 충격좌굴 신뢰성 해석)

  • 김두기
    • Journal of KSNVE
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    • v.6 no.6
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    • pp.735-747
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    • 1996
  • In this paper, buckling reliability analyses of stiffened cylinder with random initial geometric imperfection under axial impact load are performed by the combined response surface method. The effect of random geometric imperfection on the failure probability and reliability is recognized quantitatively. Buckling reliability decreases with the increase of mean value, cov of initial geometric imperfection under the same external load. Buckling probability under impact load is greater than those under static load with the same condition. From the probabilistic characteristics of imapct buckling load, relation between reliability index and safety parameter can be obtained in addition to the relation between load and reliability index. And those results can be used to determine the range of required safety parameter and acceptable imperfaction.

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A Study on the Quantification of Information Security Level (정보보안수준 계량화 연구)

  • Kim, Hyun-Soo
    • Asia pacific journal of information systems
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    • v.9 no.4
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    • pp.181-201
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    • 1999
  • This study presents an information security level index and a quantification scheme. A comprehensive survey on previous researches in information security checklists has been performed. A candidate indicator list for information security level has been developed, Desirability of each indicator has been tested by 4 criteria, They are general validity, relative importance, probability of accident and impact of accident. 67 experts' opinion has been collected and analysed. The result shows that selected indicators are a very good candidate set for the determination of information security level. A factor analysis shows indicators are well structured. There exists strong correlation between validity and probability, validity and impact, and importance and probability. A quantification scheme of information security index has been developed by experts' judgement and statistical tests.

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The Variation of Slope Stability by Ground Water Level in Railway Lines (지하수위에 따른 철도사면의 안정성 변화)

  • Kim, Hyun-Ki;Shin, Min-Ho;Shin, Ji-Soo
    • Proceedings of the KSR Conference
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    • 2008.11b
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    • pp.789-795
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    • 2008
  • Slope stability is affected by various factors. For safety management of slopes, monitoring systems have been widely constructed along railway lines. The representative data from the systems are variations of ground profile such like ground water level and pore water pressure etc. and direct displacement measured by ground clinometer and tension wire sensor. Slopes are mainly effected by rainfall and rainfall causes the decrease of factor of safety(FOS). Because FOS varies linearly by the variation of ground water level and pore pressure, it has a weak point that could not define the time and proper warning sign to secure the safety of the train. In this study, alternative of FOS such as reliability index and probability of failure is applied to slope stability analysis introducing the reliability concept. FOS, reliability index, probability of failure and velocity of probability of failure of the slopes by variation of ground water level are investigated for setting up the specification of safety management of slopes. By executing case study of a slope(ILLO-IMSUNGLI), it is showed to be applied to specification of safety management.

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Seismic damage vulnerability of empirical composite material structure of adobe and timber

  • Si-Qi Li
    • Earthquakes and Structures
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    • v.25 no.6
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    • pp.429-442
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    • 2023
  • To study the seismic vulnerability of the composite material structure of adobe and timber, we collected and statistically analysed empirical observation samples of 542,214,937 m2 and 467,177 buildings that were significantly impacted during the 179 earthquakes that occurred in mainland China from 1976 to 2010. In multi-intensity regions, combined with numerical analysis and a probability model, a non-linear continuous regression model of the vulnerability, considering the empirical seismic damage area (number of buildings) and the ratio of seismic damage, was established. Moreover, a probability matrix model of the empirical seismic damage mean value was provided. Considering the coupling effect of the annual and seismic fortification factors, an empirical seismic vulnerability curve model was constructed in the multiple-intensity regions. A probability matrix model of the mean vulnerability index (MVI) was proposed, and was validated through the above-mentioned reconnaissance sample data. A matrix model of the MVI of the regions (19 provinces in mainland China) based on the parameter (MVI) was established.

Determination of Process Capability Index considering Inspection Precision (검사정밀도를 고려한 공정능력지수의 결정)

  • 송서일;조영찬
    • Journal of Korean Society for Quality Management
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    • v.27 no.4
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    • pp.114-122
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    • 1999
  • As the rapid growth of Industrial society, many enterprises are inclined to ppm management from the traditional$3\'{o}$ management method. Therefore it is need to extend process capability index for guarantee of quality assurance level to ppm unit. Thus, in this paper, using the probability of standard normal distribution from $ 3\'{o}; to; 6\'{o}$ which was developed by Song(1997), the capability index which is proposed considers the numbers of inspection facility and quality assurance level. Also, quality assurance level is determined by considering the precision of inspection when one and two sided specification limits are given for the probability which is out of the specification limit.

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Fuzzy Binomial Proportion Test by Agreement Index (동의지수에 의한 퍼지 이항비률 검정)

  • Kang, Man-Ki;Park, Young-Rye
    • Journal of the Korean Institute of Intelligent Systems
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    • v.19 no.1
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    • pp.19-24
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    • 2009
  • We propose some properties for fuzzy binomial proportion test by agreement index. First we define fuzzy probability space and fuzzy type I error and type II error for the fuzzy probability of the two type errors. Also, we show that a fuzzy power function of performance for a fuzzy hypothesis test and drawing conclusions from the test.

Optimization of the Deep-sea Pressure Vessel by Reliability analysis (신뢰성 해석을 이용한 심해용 내압용기의 최적화)

  • JOUNG TAE-HWAN;HO IN-SIKN;LEE JAE-HWAN;HAN SEUNG-HO
    • Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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    • 2004.05a
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    • pp.190-197
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    • 2004
  • In order to consider statistical properties of probability variables used in the structural analysis, the conventional approach using the safety factor based on past experience usually estimated the safety of a structure. Also, the real structures could only be analyzed with the error in estimation of loads, material characters and the dimensions of the members. But the errors should be considered systematically in the structural analysis. In this paper, we estimated the probability of failure of the pressure vessel. And also, this paper presents sensitivity values of the random variable. Finally, we show that reliability index and probability of failure can present the tolerance limit of dimension of randam variables.

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