• 제목/요약/키워드: reliability index profile

검색결과 13건 처리시간 0.023초

교량구조시스템의 유지관리를 위한 퍼지 신뢰성해석 모델 (Fuzzy Reliability Analysis Models for Maintenance of Bridge Structure Systems)

  • 김종길;손용우;이증빈;이채규;안영기
    • 한국전산구조공학회:학술대회논문집
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    • 한국전산구조공학회 2003년도 가을 학술발표회 논문집
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    • pp.103-114
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    • 2003
  • This paper aims to propose a method that helps maintenance engineers to evaluate the damage states of bridge structure systems by using a Fuzzy Fault Tree Analysis. It may be stated that Fuzzy Fault Tree Analysis may be very useful for the systematic and rational fuzzy reliability assessment for real bridge structure systems problems because the approach is able to effectively deal with all the related bridge structural element damages in terms of the linguistic variables that incorporate systematically experts experiences and subjective judgement. This paper considers these uncertainties by providing a fuzzy reliability-based framework and shows that the identification of the optimum maintenance scenario is a straightforward process. This is achieved by using a computer program for LIFETIME. This program can consider the effects of various types of actions on the fuzzy reliability index profile of a deteriorating structures. Only the effect of maintenance interventions is considered in this study. However. any environmental or mechanical action affecting the fuzzy reliability index profile can be considered in LIFETIME. Numerical examples of deteriorating bridges are presented to illustrate the capability of the proposed approach. Further development and implementation of this approach are recommended for future research.

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교량구조물의 유지관리를 위한 신뢰성 해석 모델 (Reliability Analysis Models for Maintenance of bridge structures)

  • 김종길;손용우;이증빈;안영기
    • 한국구조물진단유지관리공학회 논문집
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    • 제8권3호
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    • pp.251-261
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    • 2004
  • 최근에 교량구조물의 부식과 노회에 대한 관심이 모아지고 있는 상황에서 부식된 철근의 불확실성은 교량구조물의 안전성 뿐만 아니라 철근콘크리트 부재의 휨강도에 영향을 미치고 있다. 이 논문에서는 이들 불확실성을 고려한 신뢰성 뼈대구조물의 거동과 최적유지관리 시나리오에 대한 검증을 제시하고 있으며, 이들 과정은 부죄된 구조물의 생애주기를 고려한 프로그램에 의해 산출한 값이며 부식구조물의 신뢰성지수 프로파일에 의한 여러 형태의 구조물에 대한 영향을 고려하여 유지관리 효과에 대해 연구 하였다.

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

  • 김현기;신민호;신지수
    • 한국철도학회:학술대회논문집
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    • 한국철도학회 2008년도 추계학술대회 논문집
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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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요인분석시 형태요인을 도출시키기 위한 자료 변환 연구 - 20대 남성 체형을 중심으로 - (Data Transition Research to Derive Shape Factor in Analyzing Factors -Centering on the body shape of males in twenties-)

  • 석혜정;김인숙
    • 대한가정학회지
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    • 제40권2호
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    • pp.67-86
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    • 2002
  • The purpose of this research is to offer a method to derive the body shapes and pose factors with resets from analyzing factors by using the measurement values of human body. 297 male subjects in their twenties participated in this study. 54 anthropometric and 35 photographic measurements were taken from each subject. Data is the several typical items selected among items and you have to make an index value by using these typical items and convert it. The index has high correlation with each item, is easy to be measured and is to be used after selecting an important item in designing prototype. With results of analyzing reliability level by each item, correlation and items that factor loading is low, the item that the correlation is high is to be removed within the range that maintains the reliability level. Five factors of the front part and seven factors of the profile came to be derived from this kind of process.

뇌졸중(腦卒中) 환자(患者)의 기능평가방법(機能評價方法)에 대(對)한 연구(硏究) (Study on function evaluation tools for stroke patients)

  • 고성규;고창남;조기호;김영석;배형섭;이경섭
    • 대한한의학회지
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    • 제17권1호
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    • pp.48-83
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    • 1996
  • Our conclusions for function evaluation tools of Stroke patients are as follows. 1. Evaluating tools of Activities of Daily Living, Katz Index, Barthel Index, Modified Barthel Index have high validity and reliability because of ease of measuring, high accuracy, consistency, sensitivity and sufficient stastistics, but they mainly measure motor function except sense, mentation, language, and social conception. Therefore cerebrovascular disease and brain injury in trauma patients with lacked acknowledgement and sensation, we are not able to apply these tools. 2. PULSES Profile is a useful scale for measuring the patient's over-all status, upper and lower limb functions, sensory components, excretary functions, and intellectual and emotional adaptabilities. It is recognized as a good, useful tool to evaluate patient's whole function. 3. Motor Assessment Scale was designed to measure the progress of stroke patients. The scale was supplemented with upper arm function items. We believe that the Motor Assessment Scale could be a useful evaluation tool with inter-rater reliability ,test-retest reliability. 4. The existing evaluation tools, Katz Index, Barthel Index, Modified Barthel Index, PULSES Profile, Motor Assessment Scale, mainly measured the rehabilitational motor function of sequela of cerebrovascular patients. On the other hand CNS & INH stroke scale can measure cerebrovascular disease patient's neurologic deficits and over-all stautus, which are recognition ability, speech status, motor function, sensory function, activities of daily living. Those scales have been recognized as useful tools to measure function of cerebrovascular disease patients and have increased in use. 5. Every function evaluation tool was recognized to have some validity and inter-rater, test-retest reliability in items of each evaluation tool and total scores of each evaluation tools, but it is thought that none of these scales have been fully validated and proved reliable. Therefore afterward, the development of a highly reliable rating system may best be accomplished by a careful comparison of several tools, using the same patients and the same observers in order to choose the most reliable items from each. 6. Ideal evaluation tools must have the following conditions; (1) It should show the objective functional statues at the same time. (2) It should be repeated consecutively to know changed function status. (3) It should be easy to observe the treatment program. (4) It should have the same result with another rater to help rater exchange information with treatment team members. (5) It should be practical and simple. (6) The patient should not suffer from the observer.

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도로면 측정 분석 시스템 개발 및 국내 도로면 특성평가 응용 연구 (Development of the Road Profiling System and Evaluation of Korean Roads Roughness Characteristics)

  • 손성효;허승진
    • 한국자동차공학회논문집
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    • 제11권3호
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    • pp.192-197
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    • 2003
  • The ‘AEIPR’(Accelerometer Established Inertial Profiling Reference) method has been applied to measure the road profile. The dynamic road profiling method using AEIPR has the advantages of cost effectiveness, measuring speed and relatively high reliability. However, it is required to improve the double integration algorithm to get the measurement results with the accuracy of hither level. In the first part of this paper, the effective double integration algorithm is suggested and the ‘Road Profiler’ software is developed on the basis of the algorithm. Road profiling tests are performed using the developed ‘Road Profiler’ system on the specially designed tracks for the durability tests and the various types of pubic roads. Test results are shown and evaluated by the international road evaluation indicies and classification.

비포장 노면의 가혹도 관리에 관한 연구 (A Study on the Severity Control of Unpaved Test Courses)

  • 양진생;구상화;이정환;강도경;이상호
    • 한국정밀공학회지
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    • 제24권2호
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    • pp.47-57
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    • 2007
  • The vibration environment essentially companied by vehicle operation on the road is determined by the shape of road surface, which is called profile. In general, the profile and severity of unpaved road is an important issue in the reliability of durability test for vehicles. In order to maintain severity of unpaved road, it is necessary to develop profilometer system. We developed profilometer system which is composed of data processing computer, power unit, air compressor and sensors. This paper focuses on the severity management of unpaved test courses using neural networks. This paper presents the maintenance range for cross-country course in CPG(Chang-won Proving Ground) and the evaluation of similarity degree between unpaved roads.

가축분뇨처리공정의 자동제어 인자 신뢰성 평가 및 적정 외부탄소원 공급량 지표 확립 (Estimation of Reliability of Real-time Control Parameters for Animal Wastewater Treatment Process and Establishment of an Index for Supplemental Carbon Source Addition)

  • 박재인;라창식
    • Journal of Animal Science and Technology
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    • 제50권4호
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    • pp.561-572
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    • 2008
  • 다양한 조건하에서 가축분뇨처리공정을 운전하면서 각 자동제어 인자의 반응을 분석하고 ORP, DO, pH(mV)-time profile를 이용한 자동제어 신뢰성을 평가하였다. 또한 무산소 조건에서의 잔존 유기물 및 미생물 자기산화에 의한 탈질율을 고려한 적정 외부탄소원 공급량 지표를 파악하였다. 실험은 45L의 유효용적을 지닌 실험실 규모의 SBR 공정을 이용하여 수행되었다. ORP-와 pH(mV)-, DO-time profile 상에서 완전질산화를 의미하는 NBP가 뚜렷하게 발현하던 중 NH4-N의 낮은 부하와 고농도 NOx-N 함유 폐수의 유입 및 불충분한 무산소 조건 제공이 이루어졌을 때 ORP-와 DO-time profile 상에서 NBP가 사라지기 시작하였으며 NOx-N의 지속적인 증가에 의해 ORP 값의 민감성이 둔화되기 시작하였다. 그러나 pH(mV)-time profile은 항상 일정한 변화패턴을 유지하면서 암모니아성 질소의 완전 질산화가 이루어졌을 때 뚜렷한 NBP를 발현하였다. NOx-N/NH4-N의 비가 80:1 수준까지 높아지는 조건하에서도 pH(mV)- time profile상에서의 이러한 안정적 NBP의 발현은 지속되었으며 발현되는 NBP는 MSC(Moving Slope Change)의 변화 패턴을 추적함에 의해 인식되도록 프로그램 할 수 있었다. pH(mV)-time profile에서의 NBP의 발현과 MSC를 이용한 자동제어시점 인식은 반응조내 NOx-N 농도가 무려 300mg/L 이상의 수준에서도 안정적이었다. 유기물 농도에 따른 자동제어 인자의 반응을 분석한 시험에서도 반응조내 유기물의 농도가 STOC 기준 약 10,000mg/L 수준으로 증가함에도 불구하고 pH(mV)-time profile 상에서의 이러한 NBP 발현은 지속되었으며 고농도 유기물 축적 하에서도 동일한 자동제어 알고리즘이 이용될 수 있음을 알 수 있었다. 잔존 유기물과 미생물 자기산화에 의한 탈질율은 약 0.4mg/L.hr로 분석되었으며 안전지수 0.1을 도입하여 산출된 NOx-N 기준 적정 외부탄소원 공급량은 0.83 STOC/NOx-N으로 파악되었다.

소아 허약 검사의 개발과 타당화 연구 (Development and validation of Pediatric Weakness Scale (PWS))

  • 채한;한상윤;천진홍;김기봉
    • 대한한방소아과학회지
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    • 제33권3호
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    • pp.30-41
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    • 2019
  • Objectives Development of objective clinical measure for analyzing pediatric weakness has been studied. However, there is no gold standard clinical measures with acceptable validity and reliability were not provided yet and these has been major issue for clinics. Methods Some Korean medicine hospital outpatients (n=324) were recruited as participants, and 55 preliminary questions were given. Pediatric Weakness Scale (PWS) with five subscales and thirty questions were developed using factor analysis and item analysis. The internal consistency of PWS subscales were examined with using Cronbach's alpha. The correlations between PWS subscales and physical characteristics of Body Mass Index (BMI) and Ponderal Index (PI) were attested using Pearson's correlation. The differences between PWS subscale scores and profiles among 3 to 13 years old children were examined using profile analysis and ANOVA by gender. Results PWS five subscales explained 49.1% of total variance, and the range of Cronbach's alpha was from 0.700 to 0.803. The range of correlation coefficient between PWS total score and five subscales was from 0.643 to 0.748, and the PWS total score was significantly (p<0.001) correlated positively with BMI (r=-0.237) and negatively with PI (r=-0.280). The scores and profiles of PWS five subscales, BMI and PI were found to be significantly different among the all age groups. Conclusions Objective and validated clinical measure for analyzing pediatric weakness with five subscales was developed in current study, and foundations for screening, managing and treating pediatric weakness during the development were established as well. This study would contribute to the integrative education and clinical practice of the Eastern and Western medicine.

표면유속을 이용한 하천 유량산정방법의 적용 및 비교 분석 (Application and Comparative Analysis of River Discharge Estimation Methods Using Surface Velocity)

  • 송재현;박석근;김치영;김형수
    • 한국방재안전학회논문집
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    • 제16권2호
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    • pp.15-32
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    • 2023
  • 홍수 유량측정은 직접 하천에 접촉하는 방식의 경우 측정인력의 안전 문제와 다수의 인력이 필요한 점 등 어려운 점이 많다. 최근 이러한 문제점을 해결하기 위해 현장에서 측정이 간편하고, 수면에 접촉하지 않는 비접촉방식의 전자파표면유속계 활용이 증가하고 있으나 돌발적이고 급변하는 현장 여건의 적용에 있어 어려움이 있다. 따라서, 홍수 상황에서 표면유속을 이용한 유량산정방법은 이론적이고, 경제적인 접근이 필요하다. 본 연구에서는 전자파표면유속계 측정자료와 수위-유량관계곡선식 자료를 수집하여 표면유속을 이용한 지표유속법과 유속분포법을 적용 및 분석하였다. 전반적으로 동수반경 3 m 이상 또는 평균유속 2 ㎧ 이상에서는 모든 방법이 측정유량 및 환산유량과 유사한 결과로 분석되었다. 그리고 대상지점 중 수위-유량관계곡선식 고수위 범위에서 최대유속 발생 위치 구간의 최대 표면유속을 이용하여 지표유속법과 유속분포법으로 유량을 산정하였고, 환산유량과의 평균 상대오차가 모두 10% 이내로 비교적 일치하였다. 홍수시 한 개의 최대 표면유속 측정과 지표유속법 및 유속분포법을 이용한 유량산정방법은 고수위 외삽 개발에 적용할 경우 외삽추정 구간에 대한 신뢰도를 제고할 수 있을 것으로 판단되었다. 따라서, 본 연구결과를 토대로 한 표면유속을 이용한 유량산정방법은 신속하고 효율적인 홍수 유량측정 방안이 될 것으로 기대된다.