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Reliability Assessment (reliability + assessment)
Selected AbstractsProbabilistic Neural Network for Reliability Assessment of Oil and Gas PipelinesCOMPUTER-AIDED CIVIL AND INFRASTRUCTURE ENGINEERING, Issue 5 2002Sunil K. Sinha A fuzzy artificial neural network (ANN),based approach is proposed for reliability assessment of oil and gas pipelines. The proposed ANN model is trained with field observation data collected using magnetic flux leakage (MFL) tools to characterize the actual condition of aging pipelines vulnerable to metal loss corrosion. The objective of this paper is to develop a simulation-based probabilistic neural network model to estimate the probability of failure of aging pipelines vulnerable to corrosion. The approach is to transform a simulation-based probabilistic analysis framework to estimate the pipeline reliability into an adaptable connectionist representation, using supervised training to initialize the weights so that the adaptable neural network predicts the probability of failure for oil and gas pipelines. This ANN model uses eight pipe parameters as input variables. The output variable is the probability of failure. The proposed method is generic, and it can be applied to several decision problems related with the maintenance of aging engineering systems. [source] The Measurement of the QT and QTc on the Neonatal and Infant Electrocardiogram: A Comprehensive Reliability AssessmentANNALS OF NONINVASIVE ELECTROCARDIOLOGY, Issue 2 2009B.S., Robert M. Gow M.B. Background: An electrocardiogram has been proposed to screen for prolonged QT interval that may predispose infants to sudden death in the first year of life. Understanding the reliability of QT interval measurement will inform the design of a screening program. Methods: Three pediatric cardiologists measured the QT/RR intervals on 60 infant electrocardiograms (median age 46 days), from leads II, V5 and V6 on three separate occasions, 7 days apart, according to a standard protocol. The QTc was corrected by Bazett's (QTcB), Fridericia's (QTCFrid), and Hodges' (QTcH) formulae. Intraobserver and interobserver reliability were assessed by intraclass correlation coefficients (ICC), limits of agreement and repeatability coefficients for single, average of two and average of three measures. Agreement for QTc prolongation (> 440 msec) was assessed by kappa coefficients. Results: QT interval intraobserver ICC was 0.86 and repeatability coefficient was 25.9 msec; interobserver ICC increased from 0.88 for single observations to 0.94 for the average of 3 measurements and repeatability coefficients decreased from 22.5 to 16.7 msec. For QTcB, intraobserver ICC was 0.67, and repeatability was 39.6 msec. Best interobserver reliability for QTcB was for the average of three measurements (ICC 0.83, reproducibility coefficient 25.8 msec), with further improvement for QTcH (ICC 0.92, reproducibility coefficient 16.69 msec). Maximum interobserver kappa for prolonged QTc was 0.77. Misclassification around specific cut points occurs because of the repeatability coefficients. Conclusions: Uncorrected QT measures are more reliable than QTcB and QTCFrid. An average of three independent measures provides the most reliable QT and QTc measurements, with QTcH better than QTcB. [source] Reliability assessment of the somatomorphic matrixINTERNATIONAL JOURNAL OF EATING DISORDERS, Issue 4 2004Guy Cafri Abstract Objective The appearance of muscularity is an emerging topic of research interest within the body image field. However, the most widely used measure to assess attitudes toward muscularity, the somatomorphic matrix, lacks pertinent reliability data. Method In response to this dearth of information, the current study assessed the test-retest reliability of this measure in samples of men and women. Results Surprisingly, the somatomorphic matrix demonstrated inadequate reliability for the majority of assessed rating protocols. Discussion The implications of this finding on assessment of the muscularity construct are discussed. © 2004 by Wiley Periodicals, Inc. Int J Eat Disord 35: 597,600, 2004. [source] Probabilistic Neural Network for Reliability Assessment of Oil and Gas PipelinesCOMPUTER-AIDED CIVIL AND INFRASTRUCTURE ENGINEERING, Issue 5 2002Sunil K. Sinha A fuzzy artificial neural network (ANN),based approach is proposed for reliability assessment of oil and gas pipelines. The proposed ANN model is trained with field observation data collected using magnetic flux leakage (MFL) tools to characterize the actual condition of aging pipelines vulnerable to metal loss corrosion. The objective of this paper is to develop a simulation-based probabilistic neural network model to estimate the probability of failure of aging pipelines vulnerable to corrosion. The approach is to transform a simulation-based probabilistic analysis framework to estimate the pipeline reliability into an adaptable connectionist representation, using supervised training to initialize the weights so that the adaptable neural network predicts the probability of failure for oil and gas pipelines. This ANN model uses eight pipe parameters as input variables. The output variable is the probability of failure. The proposed method is generic, and it can be applied to several decision problems related with the maintenance of aging engineering systems. [source] Life-Cycle Performance of RC Bridges: Probabilistic ApproachCOMPUTER-AIDED CIVIL AND INFRASTRUCTURE ENGINEERING, Issue 1 2000Dimitri V. Val This article addresses the problem of reliability assessment of reinforced concrete (RC) bridges during their service life. First, a probabilistic model for assessment of time-dependent reliability of RC bridges is presented, with particular emphasis placed on deterioration of bridges due to corrosion of reinforcing steel. The model takes into account uncertainties associated with materials properties, bridge dimensions, loads, and corrosion initiation and propagation. Time-dependent reliabilities are considered for ultimate and serviceability limit states. Examples illustrate the application of the model. Second, updating of predictive probabilistic models using site-specific data is considered. Bayesian statistical theory that provides a mathematical basis for such updating is outlined briefly, and its implementation for the updating of information about bridge properties using inspection data is described in more detail. An example illustrates the effect of this updating on bridge reliability. [source] Development of a questionnaire to measure patient-reported postoperative recovery: content validity and intra-patient reliabilityJOURNAL OF EVALUATION IN CLINICAL PRACTICE, Issue 3 2009Renée Allvin RNA MScN Abstract Aims and objectives, In this study we describe the development of a short, easy-to-use questionnaire to measure postoperative recovery and evaluate its content validity and intra-patient reliability. The questionnaire is designed to evaluate the progress of postoperative recovery and the long-term follow-up of possible effects of interventions during recovery. Methods, The study involved four steps. (1) A conceptualization and item definitions were based on a theoretical framework and a description of patients' postoperative recovery from the perspective of patients, registered nurses and surgeons; (2) Content validity of items was tested through expert judgements; (3) A test run of the questionnaire was performed to confirm its feasibility and workload requirement; and (4) The stability of the questionnaire was evaluated through intra-patient reliability assessment. Results, As a result of the operationalization process of the concept postoperative recovery, five dimensions (physical symptoms, physical functions, psychological, social, activity) and 19 items were identified. Each item was formulated as a statement in the questionnaire. Content validity was judged to be high. After the pre-test of the questionnaire a revision with refinements in the layout was made. The vast majority of items showed a high level of intra-patient reliability. Conclusion, Based on a theoretical framework and empirical data, we developed a short and easy-to-use tentative questionnaire to measure patient-reported postoperative recovery. Initial support for content validity was established. The vast majority of items showed a high level of test,retest reliability. [source] The Reliability and Validity of Birth CertificatesJOURNAL OF OBSTETRIC, GYNECOLOGIC & NEONATAL NURSING, Issue 1 2006Sally Northam Objectives:, To summarize the reliability and validity of birth certificate variables and encourage nurses to spearhead data improvement. Data sources:, A Medline key word search of reliability and validity of birth certificate, and a reference review of more than 60 articles were done. Study selection:, Twenty-four primary research studies of U.S. birth certificates that involved validity or reliability assessment. Data extraction:, Studies were reviewed, critiqued, and organized as either a reliability or a validity study and then grouped by birth certificate variable. Data synthesis:, The reliability and validity of birth certificate data vary considerably by item. Insurance, birthweight, Apgar score, and delivery method are more reliable than prenatal visits, care, and maternal complications. Tobacco and alcohol use, obstetric procedures, and delivery events are unreliable. Birth certificates are not valid sources of information on tobacco and alcohol use, prenatal care, maternal risk, pregnancy complications, labor, and delivery. Conclusions:, Birth certificates are a key data source for identifying causes of increasing U.S. infant mortality but have serious reliability and validity problems. Nurses are with mothers and infants at birth, so they are in a unique position to improve data quality and spread the word about the importance of reliable and valid data. Recommendations to improve data are presented. JOGNN, 35, 3-12; 2006. DOI: 10.1111/J.1552-6909.2006.00016.x [source] Network reliability assessment in a random environmentNAVAL RESEARCH LOGISTICS: AN INTERNATIONAL JOURNAL, Issue 6 2003S. Özekici Abstract In this paper we consider networks that consist of components operating under a randomly changing common environment. Our work is motivated by power system networks that are subject to fluctuating weather conditions over time that affect the performance of the network. We develop a general setup for any network that is subject to such environment and present results for network reliability assessment under two repair scenarios. We also present Bayesian analysis of network failure data and illustrate how reliability predictions can be obtained for the network. © 2003 Wiley Periodicals, Inc. Naval Research Logistics 50: 574,591, 2003 [source] Revisiting reliability of quantified perineal ultrasound: Bland and Altman analysis of a new protocol for the rectangular coordinate methodNEUROUROLOGY AND URODYNAMICS, Issue 7 2006S.M. Armstrong Abstract Aims This study tested the reliability of a new protocol for the rectangular coordinate method of quantifying perineal ultrasound. Methods Representative scans of healthy primiparous females were quantified by positioning a pubic bone template, drawn onto an acetate sheet containing x,y axes, over scans, by aligning the x-axis with the pubic bone central axis. Values for x (Dx) and y (Dy) located the urethrovesical junction (UVJ) at Rest, and at maximal Valsalva and Kegel. Range of motion (V,K) was calculated. Bland and Altman analysis, correlations, and t -tests determined intra- and inter-rater reliability, and variance due to designation of the pubic bone central axis (template control). Results Correlations averaged 0.72, 0.70, and 0.92 for intra-rater, inter-rater, and template control experiments. Dx Rest, Dx Kegel, and V,K were reliable in all experiments. First and second measures for inter-rater Dy Rest and Dy Kegel, and template control Dy Valsalva were significantly different. Bland and Altman analysis showed Dy Rest, Dy Kegel, and Dx and Dy Valsalva for both reliability experiments to have limits of agreement (LOA's) large enough to explain ,50% of the actual value ranges. Template control LOA's explained ,30% of the actual value ranges. Conclusions The reliability of this protocol varied according to the conditions analyzed; accurate reliability assessment of all conditions required Bland and Altman analysis; and the designation of the pubic bone central axis remained a source of variance between investigators. Our results suggest Bland and Altman analysis be used with each study that quantifies perineal ultrasound. Neurourol. Urodynam. 25:731,738, 2006. © 2006 Wiley-Liss, Inc. [source] Psychometric Properties of Commonly Used Low Back Disability Questionnaires: Are They Useful for Older Adults with Low Back Pain?PAIN MEDICINE, Issue 1 2009Gregory E. Hicks PT ABSTRACT Objectives., To evaluate the psychometric properties of two commonly used low back pain (LBP) disability questionnaires in a sample solely comprising community-dwelling older adults. Design., Single-group repeated measures design. Setting., Four continuing care retirement communities in Maryland and in Virginia. Participants., Convenience sample of 107 community-dwelling men and women (71.9%) aged 62 years or older with current LBP. Outcome Measures., All participants completed modified Oswestry Disability (mOSW) and Quebec Back Pain Disability (QUE) questionnaires, as well as the Medical Outcomes Survey Short-Form 36 questionnaire at baseline. At follow-up, 56 participants completed the mOSW and the QUE for reliability assessment. Results., Test,retest reliability of the mOSW and QUE were excellent with intraclass correlation coefficients of 0.92 (95% confidence interval [CI]: 0.86, 0.95) and 0.94 (95% CI: 0.90, 0.97), respectively. Participants with high pain severity and high levels of functional limitation had higher scores on the mOSW (P < 0.0001) and QUE (P < 0.001) scales than other participants, which represents good construct validity for both scales. The threshold for minimum detectable change is 10.66 points for the mOSW and 11.04 points for the QUE. Both questionnaires had sufficient scale width to accurately measure changes in patient status. Conclusions., It appears that both questionnaires have excellent test,retest reliability and good construct validity when used to evaluate LBP-related disability for older adults with varying degrees of LBP. Neither questionnaire appears to have superior psychometric properties; therefore, both the Oswestry and Quebec can be recommended for use among geriatric patients with LBP. [source] Comparison of finger plethysmograph to ECG in the measurement of heart rate variabilityPSYCHOPHYSIOLOGY, Issue 2 2002Nicholas D. Giardino Two experiments compared finger plethysmograph (FP) to electrocardiogram (ECG) in providing accurate heart periods for use in heart rate variability (HRV) calculations. In Experiment 1, simultaneous ECG and FP recordings were taken from 16 healthy subjects at rest. In Experiment 2, 10 additional healthy subjects were recorded at rest and during the Stroop Color-Word Test. In both studies, high correlations were found between FP-derived and ECG-derived band variance for high and low frequency HRV at rest. But, during the Stroop task, correlations were strongly diminished. In addition, under both conditions, HRV measures were significantly higher using the FP signal. Thus, FP may be adequate for determining HRV at rest, but, for experimental use, ECG may still be recommended. Nonetheless, further studies that include test,retest reliability assessment of both data collection techniques are warranted before a more certain determination can be made. [source] The Validity and Reliability of the Reflux Finding Score (RFS),THE LARYNGOSCOPE, Issue 8 2001Peter C. Belafsky MD Abstract Background The evaluation of medical and surgical outcomes relies on methods of accurately quantifying treatment results. Currently, there is no validated instrument whose purpose is to document the physical findings and severity of laryngopharyngeal reflux (LPR). Objective To evaluate the validity and reliability of the reflux finding score (RFS). Methods Forty patients with LPR confirmed by double-probe pH monitoring were evaluated pretreatment and 2, 4, and 6 months after treatment. The RFS was documented for each patient at each visit. For test,retest intraobserver reliability assessment, a blinded laryngologist determined the RFS on two separate occasions. To evaluate interobserver reliability, the RFS was determined by two different blinded laryngologists. Results The mean age of the cohort was 50 years (± 12 standard deviation [SD]). Seventy-three percent were women. The RFS at entry was 11.5 (± 5.2 SD). This score improved to 9.3 (± 4.7 SD) at 2 months, 7.3 (± 5.5 SD) at 4 months, and 6.1 (± 5.2 SD) at 6 months of treatment (P <.001 with trend). The mean RFS for laryngologist no. 1 was 10.8 (± 4.1 SD) at the initial screening and 10.8 (± 4.0 SD) at the repeat evaluation (r = 0.95, P <.001). The mean RFS for laryngologist no. 2 was 11.1 (± 3.8 SD) at the initial screening and 10.9 (± 3.7 SD) at the repeat evaluation (r = 0.95, P <.001). The correlation coefficient for interobserver variability was 0.90 (P <.001). Conclusions The RFS accurately documents treatment efficacy in patients with LPR. It demonstrates excellent inter- and intraobserver reproducibility. [source] Überwachung und Analyse der Lebensdauer von TunnelbauwerkenBETON- UND STAHLBETONBAU, Issue 1 2007Konrad Bergmeister Prof. Dipl.-Ing. Im Tunnelbau bildet die Überwachung der signifikanten Einwirkungs- und Strukturparameter während der Bauphase und des Betriebs die Basis für die Bewertung des Zustands und der Sicherheit des Bauwerks. Die erfassten Daten stellen des Weiteren die Grundlage zur nummerischen und mechanischen Modellbildung dar, um eine effiziente Entscheidungsfindung und Maßnahmenplanung zu gewährleisten. Die Überwachung beinhaltet die Erfassung und Bewertung der geologischen Gegebenheiten, der induzierten Auswirkungen während des Vortriebs und die kontinuierliche Kontrolle für den weiteren Betrieb und Unterhalt des Bauwerks. Methoden der Bauwerksüberwachung und Diagnose stellen aufgrund der quantitativ erfassten Systemparameter ein wesentliches Element für die Zuverlässigkeitsanalyse dar. Die geeignete Wahl von Kontroll- und Messinstrumenten ist jedoch nur einen Teilaspekt der Bauwerksüberwachung. Die Auswertung und Interpretation der erhobenen Daten, die Gegenüberstellung mit den normativen Anforderungen und Grenzwerten, die Anpassung der analytischen Modellannahmen aufgrund des Vergleichs von gemessenen und berechneten Daten zeigen die Komplexität dieses Aufgabengebietes. Monitoring and Analysis of Durability of Tunnels Monitoring continuously the decisive parameters, during both the construction and the operation phase, provides the quantitative basis for safety and condition assessment, analytical modelling and decision making. This includes evaluating the conditions and induced effects during excavation and construction, and continues during operation in terms of maintenance decision making and reliability assessment. The utilisation of monitoring devices and measurement elements is however only the start of monitoring field performance. Interpretation of the acquired data is equally important, namely the validation of compliance with normative specifications and the comparison of measured and calculated data in order to evaluate analytical model assumptions. [source] Translation and validation of a Chinese language version of the Early Childhood Oral Health Impact Scale (ECOHIS)INTERNATIONAL JOURNAL OF PAEDIATRIC DENTISTRY, Issue 6 2009GILLIAN H. M. LEE Objective., This study aimed to adapt the Early Childhood Oral Health Impact Scale (ECOHIS) for pre-school children in a Chinese speaking community and to investigate its psychometric properties (validity and reliability). Methods., A Chinese language version of the ECOHIS was derived through a forward,backward translation and tested for face and content validity among a focus group. A convenient sample of pre-school children (n = 111) was recruited (including a sub-sample with early childhood caries and caries-free children). Parents of the children self-completed the derived Chinese-ECOHIS measure. Validity of the measure was assessed by investigating the relationship between dental caries status and Chinese-ECOHIS scores (construct and criterion validity). A sub-sample of the parents repeated the ratings of the measure to enable reliability assessments. Both internal and test,retest reliability were determined. Results., A Chinese version of ECOHIS was derived with minor modification to the original version. Chinese-ECOHIS scores were associated with children's caries experience (dmft) (r = 0.66, P < 0.05) supporting convergent validity. In addition, variations in ECOHIS scores were apparent with respect to caries and caries-free groups (P < 0.001), supporting the ability to distinguish between patient groups. Cronbach's alpha values (internal reliability) for total ECOHIS score were 0.91 and intraclass correlation coefficient value (test,retest reliability) was 0.64. Conclusions., A Chinese version of the ECOHIS was developed and demonstrated acceptable validity and reliability. These findings can enable assessments of pre-school child oral health-related quality of life in Chinese speaking communities. [source] Interobserver reliability of the Nail Psoriasis Severity IndexCLINICAL & EXPERIMENTAL DERMATOLOGY, Issue 2 2007. Aktan Summary Background., Because the Psoriasis Area and Severity Index (PASI) does not consider the severity of nail disease, a scale that assesses the extent of involvement of psoriatic nails is needed. A new grading system, the Nail Psoriasis Severity Index (NAPSI) has been proposed. Aims., The purpose of this study was to assess the interobserver reliability of NAPSI. Methods., The nail features of 25 patients with psoriasis with nail involvement were evaluated and graded by three dermatologists for total NAPSI scores and nail scores. The quadrants of all nails were examined for the presence of matrix and bed features. Total NAPSI score (0,160) of patients and nail score (0,32) of the individual nails were calculated. Interobserver reliability assessments were performed by computing intraclass correlation coefficients (ICC; two-way mixed model, consistency definition). Results., The ICC(3,1) results for total NAPSI score and nail score were found to be 0.781 and 0.649, respectively. The ICC(3,1) for nail-bed and nail-matrix features were 0.869 and 0.584, respectively, in the total NAPSI scoring system, and 0.705 and 0.603, respectively, in the nail scoring system. Conclusion., Moderate to good agreement of scoring with the NAPSI was determined among the observers in this study. Our results suggest that scoring for nail-bed features seems to be more reliable than scoring for nail-matrix features. [source] | ||||||||||||||||