• Title/Summary/Keyword: reliability assessment

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Inter-Rater Reliability of Chedoke-McMaster Stroke Assessment for Stroke Patients (뇌졸중환자 평가를 위한 Chedoke-McMaster Stroke Assessment의 측정자간 신뢰도)

  • Won, Jong-Hyuk;Kim, Yong-Wook
    • Physical Therapy Korea
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    • v.4 no.3
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    • pp.45-60
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    • 1997
  • This study was performed to determine the inter-rater reliability of the Chedoke-McMaster Stroke Assessment translated in Korean. This measures the physical impairments and disabilities that impact on the lives of individuals with stroke. The purposes of this measure were 1) to stage motor recovery to classify individuals in terms of clinical characteristics, 2) to predict rehabilitation outcomes, and 3) to measure clinically important change in physical function. Twenty-two subjects from physical therapy unit were assessed by two physical therapists. The ratings were compared by Spearman's rank correlation The correlation between two raters ranged from 0.85 to 0.98. Inter-rater reliability coefficient for total scores ranged from 0.95 to 0.97. This study confirms that the Chedoke-McMaster Stroke Assessment yields reliable results.

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A Study on the Substation Reliability Assessment Using Weibull Distribution (와이블분포를 이용한 변전소 신뢰도 평가에 관한 연구)

  • Kim, Gwang-Won
    • The Transactions of the Korean Institute of Electrical Engineers A
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    • v.51 no.1
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    • pp.7-14
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    • 2002
  • In power system study, relibility assessment has been an important topic during past several decards because sudden power interruption can bring about enormous economic loss. although the size of a substation is smaller than that of generation system or transmission system, switching actions after fault(s) make reliability assessment of substation rather complex situations such as switching actions easily and permit various probability distributions in describing substation elements. Despite this ability of Monte Carlo simulation, one-parameter exponential distribution is still popular in this reliability assessment. This paper examines the characteristics of several two-parameter probability distributions, and offers new parameter decision rule based on average and variance of the target to be modelled. In case study, this paper shows the profits by using Weibull distribution which is one of two-parameter probabilistic distributions instead of exponential one.

Probabilistic-based assessment of composite steel-concrete structures through an innovative framework

  • Matos, Jose C.;Valente, Isabel B.;Cruz, Paulo J.S.;Moreira, Vicente N.
    • Steel and Composite Structures
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    • v.20 no.6
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    • pp.1345-1368
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    • 2016
  • This paper presents the probabilistic-based assessment of composite steel-concrete structures through an innovative framework. This framework combines model identification and reliability assessment procedures. The paper starts by describing current structural assessment algorithms and the most relevant uncertainty sources. The developed model identification algorithm is then presented. During this procedure, the model parameters are automatically adjusted, so that the numerical results best fit the experimental data. Modelling and measurement errors are respectively incorporated in this algorithm. The reliability assessment procedure aims to assess the structure performance, considering randomness in model parameters. Since monitoring and characterization tests are common measures to control and acquire information about those parameters, a Bayesian inference procedure is incorporated to update the reliability assessment. The framework is then tested with a set of composite steel-concrete beams, which behavior is complex. The experimental tests, as well as the developed numerical model and the obtained results from the proposed framework, are respectively present.

Time Dependent Reliability Analysis of the Degrading RC Containment Structures Subjected to Earthquake Load (지진하중을 받는 RC 격납건물의 열화에 따른 신뢰성 해석)

  • 오병환
    • Proceedings of the Earthquake Engineering Society of Korea Conference
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    • 2000.04a
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    • pp.233-240
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    • 2000
  • Nuclear power plant structures may be exposed to aggressive environmental effects than may cause their strength and stiffness to decrease over their service lives, Although the physics of these damage mechanisms are reasonably well understood and quantitative evaluation of their effects on time-dependent structural behavior is possible in some instances such evaluations are generally very difficult and remain novel. The assessment of existing RC containment in nuclear power plants for continued service must provide quantitative evidence that they are able to withstand future extreme loads during a service period with an acceptable level of reliability. Rational methodologies to perform the reliability assessment can be developed from mechanistic models of structural deterioration using time-dependent structural reliability analysis to take earthquake loading uncertainties into account. The final goal of this study is to develop the reliability analysis of RC containment structures. The cause of the degrading is first clarified and the reliability assessment has been conducted. By introducing stochastic analysis based on random vibration theory the reliability analysis which can determine the failure probabilities has been established.

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Reliability Assessment of Tubular Markers Used for Road Safety Facilities (도로안전시설용 시선유도봉의 신뢰성 평가)

  • Koo, Hyun-Jin;Yoon, Ye-Seok
    • Journal of Applied Reliability
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    • v.12 no.2
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    • pp.91-103
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    • 2012
  • Tubular markers for road safety facilities are used to lead the driver's sight line and separate the lanes on the road. Such tubular markers are usually installed on the road and frequently hit by vehicles, they are accordingly requested to assure the product durability. The traditional evaluation method of tubular markers include only quality tests of the material properties. However, most of consuming agencies in charge of road management at fields have proposed problems on long-term performance of the products hit by vehicles under various weather conditions. Therefore, the objectives of this study are to develop the reliability test methods and equipments to simulate the product failures of tubular markers due to vehicle collision and wheel compression and the delamination and discoloration of reflection sheets attached on the surface of the products under high and low temperatures.

A study on the Reliability Analysis of Nuclear Steel Containment Structures Subject to Internal Pressure (내압을 받는 원전 강재격납건물의 신뢰성 해석)

  • 오병환;최성철
    • Proceedings of the Korea Concrete Institute Conference
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    • 1999.04a
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    • pp.229-232
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    • 1999
  • Nuclear power plant structures may be exposed to aggressive environmental effects that may cause their damage mechanisms are reasonably well understood and quantitative evaluation of their effects on time-dependent structural behavior is possible in some instances, such evaluations are generally very difficult and remain novel. The assessment of existing steel containment in nuclear power plants for continued service must provide quantitative evidence that they are able to withstand future extreme loads during a service period with an acceptable level of reliability. Rational methodologies to perform the reliability assessment can be developed from mechanistic models of structural deterioration, using time-dependent structural reliability analysis to take loading and strength uncertainties into account. The final goal of this study is to develop the analysis method for the analysis for the reliability of containment structures. The cause and mechanism of corrosion is first clarified and the reliability assessment method has been established. By introducing the equivalent normal distribution, the procedure of reliability analysis which can determine the failure probabilities has been established.

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Reliability Assessment Criteria of Motorized Roller Conveyor (자체구동롤러 컨베이어의 신뢰성 평가기준)

  • Kim, Young-Joo;Go, Hee-Yang;Han, In-Sup;Kim, Yong Soo
    • Journal of the Korean Society of Manufacturing Technology Engineers
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    • v.24 no.5
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    • pp.521-529
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    • 2015
  • Owing to a reliance on imported products from Europe and Japan, the use of logistics equipment with poor energy efficiency coupled with high maintenance costs can lead to high operating costs for some domestic logistic centers. To lower their operating costs, the logistic centers use motorized roller conveyors. In order to commercialize this process, it is necessary to establish the test criteria and assess the reliability of the process. Currently, there exists no standard verification method to test the reliability of motorized roller conveyors. In this study, we propose reliability assessment criteria for a: i) reliability test, ii) environmental test, iii) safety test, and iv) lifetime test.

Research of Reliability Assessment for Inchon International Airport (인천국제공학의 신뢰도 산정에 관한 연구)

  • Kim, Yong-Ha;Lee, Buhm;Choi, Sang-Kyu;Roh, Dae-Seck;Moon, Jeong-Ho;Min, Sung-Jun
    • Proceedings of the KIEE Conference
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    • 1998.11a
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    • pp.235-238
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    • 1998
  • This paper presents a reliability assessment for Inchon International Airport. Reliability of electrical parts and load points is calculated through Network reduction method and Failure modes & effective analysis method. And reliability indices of distribution system is calculated. By using reliability and reliability indices, assessment of distribution system of Inchon International Airport is executed. This results makes it possible to improve reliability.

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

  • Hwang, Seong-Soo;Kim, Pu-Reum;Won, Ji-In;Yoo, Seon-Ju;Yoon, Jun-Byung;Lee, Keun-Woo;Lee, Wang-Jae
    • PNF and Movement
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    • v.10 no.1
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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.

Reliability and Validity of Gait Assessment Tools for Elderly Person (노인의 보행에 대한 평가 도구의 신뢰도와 타당도 조사 연구)

  • Kim, Jae-Hyun
    • The Journal of Korean Physical Therapy
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    • v.21 no.1
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    • pp.41-48
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    • 2009
  • Purpose: The examine the Reliability and Validity of the modified Emory Functional Ambulation Profile (mEFAP), Tinetti. Gait (TG), Timed Up & Go Tes t (TUG), Comfortable Gait Speed (CGS), Berg Balance Scale (BBS) in assessing gait function and balance in elderly person. Methods: The 45 community-dwelling subjects were participated in this study. Reliability was determined by intra-class correlation coefficient (ICC$_{3,1}$), Bland and Altman method (Standard Error of Measurement (SEM), Smallest Real Difference (SRD)). Results: Validity was examined by correlation the mEFAP, TG, TUG, CGS, BBS. The intra-rater reliability were High (ICC$_{3,1}$ : mEFAP=0.95, TG=0.96, TUG=0.94, CGS=0.96, BBS=0.92) and Absolute reliability were excellent (SEM: mEFAP=1.90, TG=0.21, TUG=0.28 CGS=0.25, BBS=0.52), (SRD: mEFAP=5.26, TG=0.58, TUG=0.77, CGS=0.69, BBS=1.44). There were significant correlations between assessment tool (r=.0.58$\sim$0.78, p<0.01) indicating good validity. Our results provide strong evidence that the assessment tool has good reliability, validity for assessing elderly person undergoing rehabilitation. Conclusion: The gait assessment tool is a useful scale for measuring walking function and recovery in elderly person.

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