• 제목/요약/키워드: reliability Index(B)

검색결과 42건 처리시간 0.022초

말뚝 기초지지력에 대한 안전율과 신뢰도지수 평가 (Relations of Safety Factor and Reliability Index for Pile Load Capacity)

  • 김대호;이준환
    • 한국지반공학회:학술대회논문집
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    • 한국지반공학회 2006년도 춘계 학술발표회 논문집
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    • pp.466-475
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    • 2006
  • Reliability analysis between safety factor and reliability index for driven and bored pile load capacity was analyzed in this study. 0.1B, Chin, De Beer, and Davisson's methods were used for determining pile load capacity by using load-settlement curve from pile load test. Each method define ultimate, yield and allowable pile load capacities. LCPC method using CPT results was performed for comparing with results of pile load test. Based on FOSM analysis using load factors, it is obtained that reliability indices for ultimate pile load capacity were higher than those of yield and allowable condition. Present safety factor 2 for yield and allowable load capacities are not enough to satisfy target reliability index $2.0\sim2.5$. However, it is sufficient for ultimate pile load capacity using safety factor 3.

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교량 점검신뢰도 분석법 개발과 향상방안 (Development of Bridge Inspection Reliability and Improvement Strategy)

  • 정유석;김우석;이일근;이재하
    • 한국구조물진단유지관리공학회 논문집
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    • 제20권5호
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    • pp.50-57
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    • 2016
  • 교량의 안전은 점검에 의해 보장된다. 그리고 교량의 유지관리는 점검결과를 토대로 시작된다. 따라서 점검결과는 '교량의 안전'과 '효율적인 유지관리'를 위한 가장 중요한 정보이다. 따라서 본 논문에서는 교량의 점검신뢰도를 평가하고 이를 제고 할 수 있는 방안을 제시하고자 한다. 이를 위해 본 논문에서는 교량의 점검신뢰도를 평가 할 수 있는 세 가지 점검신뢰도를 제시하였다: 명목점검신뢰도, 실질점검신뢰도, DS명목점검신뢰도. 교량의 점검신뢰도 분석 방법은 정밀안전진단결과를 참값으로 간주하고 당해년도 정밀(정기)점검과 차년도 정밀안전 진단결과를 비교하였다. 인적오류를 고려한 DS명목신뢰도를 기준으로 현재 고속도로교량의 점검신뢰도 85%로 양호한 편으로 평가 된다. 이는 현재 고속도로 교량의 평균공용연수가 13년으로 대부분의 교량이 'A'와 'B'등급에 집중적으로 분포되어 상태변화가 크지 않기 때문인 것으로 판단된다. 점검신뢰도를 제고하기 위해서는 점검자의 역량을 강화하고 전문점검인력 육성이 필요하며 점검결과에 대해 QC(Quality Control, 품질관리)를 실시하여 점검결과의 신뢰도 향상이 필요하다.

궤도구조 변경에 따른 열차 진동 추정식 제안 (Suggestion for Train Vibration Equations based on Change in Track System)

  • 김응록;박연수;강성후;박선준;김흥기
    • 한국철도학회논문집
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    • 제5권1호
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    • pp.48-54
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    • 2002
  • This research estimated decreased vibration level as quantitative according to change of track system on Seoul Subway Line No. 1 from existing ballasted track system(Pandrol type clip) to concrete track system(Youbgdan type isolation rubber clip). Following change to concrete system, vibration level at tunnel floor decreased between 4-8dB(V). Vibration equations suggested in this paper consider the velocity of train and can estimate quantitative vibration response. These are divided by ultimate limit state($\beta$=0), serviceability limit state($\beta$=1.28) and safety state($\beta$=3), respectively. The reliability index, $\beta$=0, means 50% data line obtained by least squares best-fit line. The reliability index $\beta$=1.28 and 3 represent boundaries below 90% and 99.9% respectively.

Reliability analysis of a mechanically stabilized earth wall using the surface response methodology optimized by a genetic algorithm

  • Hamrouni, Adam;Dias, Daniel;Sbartai, Badreddine
    • Geomechanics and Engineering
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    • 제15권4호
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    • pp.937-945
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    • 2018
  • A probabilistic study of a reinforced earth wall in a frictional soil using the surface response methodology (RSM) is presented. A deterministic model based on numerical simulations is used (Abdelouhab et al. 2011, 2012b) and the serviceability limit state (SLS) is considered in the analysis. The model computes the maximum horizontal displacement of the wall. The response surface methodology is utilized for the assessment of the Hasofer-Lind reliability index and is optimized by the use of a genetic algorithm. The soil friction angle and the unit weight are considered as random variables while studying the SLS. The assumption of non-normal distribution for the random variables has an important effect on the reliability index for the practical range of values of the wall horizontal displacement.

Reliability evaluation of steel truss bridge due to traffic load based on bridge weigh-in-motion measurement

  • Widi Nugraha;Indra Djati Sidi;Made Suarjana;Ediansjah Zulkifli
    • Structural Monitoring and Maintenance
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    • 제9권4호
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    • pp.323-336
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    • 2022
  • Steel truss bridge is one of the most widely used bridge types in Indonesia. Out of all Indonesia's national roads, the number of steel truss bridges reaches 12% of the total 17,160 bridges. The application of steel truss bridges is relatively high considering this type of bridge provides advantages in the standardization of design and fabrication of structural elements for typical bridge spans, as well as ease of mobilization. Directorate of Road and Bridge Engineering, Ministry of Works and Housing, has issued a standard design for steel truss bridges commonly used in Indonesia, which is designed against the design load in SNI 1725-2016 Bridge Loading Standards. Along with the development of actual traffic load measurement technology using Bridge Weigh-in-Motion (B-WIM), traffic loading data can be utilized to evaluate the reliability of standard bridges, such as standard steel truss bridges which are commonly used in Indonesia. The result of the B-WIM measurement on the Central Java Pantura National Road, Batang - Kendal undertaken in 2018, which supports the heaviest load and traffic conditions on the national road, is used in this study. In this study, simulation of a sequences of traffic was carried out based on B-WIM data as a moving load on the Australian type Steel Truss Bridge (i.e., Rangka Baja Australia -RBA) structure model with 60 m class A span. The reliability evaluation was then carried out by calculating the reliability index or the probability of structural failure. Based on the analysis conducted in this study, it was found that the reliability index of the 60 m class Aspan for RBA bridge is 3.04 or the probability of structural failure is 1.18 × 10-3, which describes the level of reliability of the RBA bridge structure due to the loads from B-WIM measurement in Indonesia. For this RBA Bridge 60 m span class A, it was found that the calibrated nominal live load that met the target reliability is increased by 13% than stated in the code, so the uniform distributed load will be 7.60 kN/m2 and the axle line equivalent load will be 55.15 kN/m.

Reliability of Scapular Downward Rotation Measurement in Subjects With Scapular Downward Rotation Syndrome

  • Choi, Woo-Jeong;Lee, Ji-Hyun;Jeong, Hyo-Jung;Yoon, Tae-Lim;Cynn, Heon-Seock
    • 한국전문물리치료학회지
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    • 제21권3호
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    • pp.73-79
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    • 2014
  • The purposes of the current study were to (1) estimate the inter-rater agreement for visual assessment of scapular downward rotation (SDR), (2) develop the scapular downward rotation index (SDRI) as a method to measure SDR objectively and quantitatively, and (3) analyze the intra- and inter-rater reliability of the SDRI. Twenty subjects with scapular downward rotation syndrome (SDRS) were recruited for this study. The visual assessment and the measurement for the SDRI were conducted by two examiners in two sessions each. The SDRI [$(a-b){\div}a{\times}100$] is calculated with the measurement of two linear distances: One is a perpendicular distance from the root of the scapular spine to the thoracic mid-line (a), and the other is a perpendicular distance from the inferior angle of the scapula to the thoracic mid-line (b). Cohen's kappa coefficient was calculated to estimate the inter-rater agreement for visual assessment. Intra-class correlation coefficients (ICCs) with a 95% confidence interval (CI), the standard error of measurement, and minimal detectable differences were calculated to assess intra- and inter-rater reliability of SDR measurement using the SDRI. The results indicated that the kappa coefficient of inter-rater agreement for visual assessment was fair (${\kappa}=.21$). The intra-rater reliability of SDR measurement using the SDRI was excellent for examiner 1 (ICC=.92, 95% CI=.78~.97) and good for examiner 2 (ICC=.82, 95% CI=.55~.93). The inter-rater reliability was moderate (ICC=.73, 95% CI=.32~.89). These findings showed that SDR measurement using the SDRI for subjects with SDRS may be considered reliable and better than the visual assessment.

간호강도에 의한 환자분류도구의 신뢰도 및 타당도 검증 (Reliability and Validity Tests of Patient Classification System Based on Nursing Intensity)

  • 박정호;김은혜
    • 간호행정학회지
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    • 제13권1호
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    • pp.5-16
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    • 2007
  • Purpose: This study is to verify the validity and reliability of classified items and criteria of the patient classification system(PCS) based on Park's definition of nursing intensity. Methods: An expert group of 8 persons verified the content validity of the tools. The 1817 inpatients at a tertiary hospital in Seoul, Korea were classified into 4 groups according to two tools for verifying concurrent validity and interraters' reliability. These verifications were performed from September to October, 2004. Results: Nursing domains of the tools have been divided into 12 items: hygiene, nutrition, elimination, exercise & activity, education & counseling, emotional support, communication & consciousness, treatment & examination, medication, measurement & observation, coordination of multidisciplinary team, admission & discharge & transfer management. Content validity was verified by the content validity index(above 0.75 in all 12 areas). Interraters' reliability was no significant difference in the results of the patient classification between the two raters(A group 93.75%. B group 88.24%). Concurrent validity was also verified by the agreement of two tools(73.7%). Conclusion: These results showed that the reliability and validity of the PCS based on the nursing intensity were verified. These will use an data for nursing productivity in the future.

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말뚝 기초지지력에 대한 안전율과 신뢰도지수 평가 (Relations of Safety Factor and Reliability for Pile Load Capacity)

  • 김대호;김민기;황성욱;박영환;이준환
    • 한국지반공학회논문집
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    • 제22권11호
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    • pp.65-73
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    • 2006
  • 최근 신뢰성 이론에 바탕을 둔 한계상태설계법(Limit State Design)이 국제적으로 도입되고있는 추세이다. 이에 본 연구에서는 사질토 지반에 근입된 항타 및 현장타설 말뚝의 지지력 산정법에 대한 신뢰도지수와 안전율과의 관계를 규명하고자 하였다. 본 연구는 말뚝 직경의 10% 침하 시 지지력을 결정하는 방법(0.1B), Chin의 방법, De Beer의 방법과 Davisson의 방법에 대한 말뚝 지지력 산정결과를 비교 분석하였고, 말뚝의 지지력 산정 시 유용하게 활용되는 CPT결과를 통한 말뚝의 지지력 산정법 중에서 LCPC법에 의한 지지력과의 비교를 통해 FOSM법을 바탕으로 각 산정 법에 대한 신뢰도를 평가하였다 각 말뚝지지력 해석 방법에 따른 안전율과 신뢰도지수 관계 분석결과, 극한지지력을 규정하는 0.1B와 Chin의 방법에 대한 신뢰도지수가 De Beer와 Davisson에 의한 신뢰도지수보다 높은 것으로 나타났으며, 목표신뢰도지수 $2.0{\sim}2.5$를 기준으로 하여 항타 말뚝에서의 안전율 2는 방법에 따라 다소 증대될 필요가 있고, 현장 타설 말뚝에서는 극한 지지력 확인시 안전율 3보다 작게 적용할 수 있는 여지가 있음을 확인하였다.

무역항 및 연안항 피복재의 파괴확률과 부분안전계수 해석 (Analysis of Probabilities of Failure and Partial Safety Factors of Armor Units on Tranding and Coastal Harbors)

  • 이철응;박동헌
    • 산업기술연구
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    • 제28권B호
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    • pp.157-165
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    • 2008
  • Level II AFDA and Level III MCS reliability models are applied to analyze the stability of armor units on trading and coastal harbors in Korea. Hudson's formula and Van der Meer's formula are used in this reliability analysis. Also, probability density functions of reliability index and probability of failure are derived by the additional analysis. In addition, the partial safety factors of all harbors related to armor units can be straightforwardly evaluated by the inverse-reliability method. The upper and lower limits and average level of partial safety factors can be statistically investigated with the results of all cases applied in this paper. Therefore, it may be possible to design armor units of new breakwaters including the uncertainty of random variable and target level by using the present results.

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뇌졸중 환자에 대한 상지기능 평가도구의 검사자간 신뢰도 (Interrater Reliability of Upper Extremity Function Assessment on Stroke)

  • 황성수;김푸름;원지인;유선주;윤준병;이근우;이왕재
    • PNF and Movement
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    • 제10권1호
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    • pp.1-7
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    • 2012
  • Purpose : To verify the interrater reliability of upper extremity function assessment among three tools(Wolf motor function test, Motor assessment scale, Fugl-meyer assessment scale). Methods : The subjects of this study 40 (20 was physical therapists and 20 was physical therapy students). For the test one patients with chronic hemiparesis after stroke participated in the study. The Wolf Motor Function Test consists of 16 functional tasks. The motor assessment scale consists of 3 functional tasks. The fugl-meyer assessment scale consists of 8 functional tasks. All test sessions were videotaped and scored by 40 subjects. Analysis : The data was analysis by SPSS PC 14.0 with Cronbach alpha Coefficients, intraclass Correlation Coefficients Kendall tau-b value. Results : WMFT was highly scored in Cronbach's value, Cronbach's ${\alpha}=0.819$ that means high interrater reliability among assessment. WMFT was highly scored all items in p-value except one item, that means high p-value between therapists and students. WMFT was highly scored in Intrarater correlation coefficient (ICC) = 0.79, that means high interrater reliability of each examination item. WMFT was low index of coincidence from all items, MAS was low index of coincidence from a tim and FMA was low index of coincidence from 4 items. Conclusion : The interrater reliability of WMFT were compared with MAS, FMA and highly verified. WMFT can be more useful tool among upper extremity function assessment.