Search results for " RELIABILITY"
showing 10 items of 557 documents
Approximate solution of the Fokker-Planck-Kolmogorov equation
2002
The aim of this paper is to present a thorough investigation of approximate techniques for estimating the stationary and non-stationary probability density function (PDF) of the response of nonlinear systems subjected to (additive and/or multiplicative) Gaussian white noise excitations. Attention is focused on the general scheme of weighted residuals for the approximate solution of the Fokker-Planck-Kolmogorov (FPK) equation. It is shown that the main drawbacks of closure schemes, such as negative values of the PDF in some regions, may be overcome by rewriting the FPK equation in terms of log-probability density function (log-PDF). The criteria for selecting the set of weighting functions i…
Improved Global-Local Method for Ultrasonic Guided Wave Scattering Predictions in Composite Waveguides and Defects
2023
Abstract As structures increase in complexity, in the use of high-performing materials and designs, their health assessment becomes increasingly challenging. Ultrasonic guided waves (UGWs) have shown to be very promising in the inspection of large (i.e. aerospace components) attenuating (i.e. composite materials) structures and have been successfully employed for damage detection in a variety of fields. The intrinsic complex nature of UGWs, due to their dispersive behavior, combined with the structural complexity of the applications, though, makes the interpretation of UGW inspections very challenging. Numerical simulations of UGW propagation become crucial to this end and have been address…
The impact of work accidents experience on causal attributions and worker behaviour
2008
Abstract It has recently been suggested that the experience of work accidents is an important variable to be considered as a predictor of workers’ perceptions (e.g. causal attributions) and behaviours. Departing from the literature, this study has two goals: (1) to analyse the relationship among work accident experience, causal attribution of accidents and workers’ behaviour; and (2) to test causal attributions as a mediating variable in the relationship between work accident experience and workers’ behaviour. To test the stability of the results, the same analyses have been performed in two Portuguese organizations, one in an industrial context and the other in an R&D context. In the indus…
Safety self-efficacy and internal locus of control as mediators of safety motivation – Randomized controlled trial (RCT) study
2019
Abstract Behavioral factors play a fundamental role in preventing occupational injuries and accidents. Previous studies have shown that engagement in safety behavior is influenced by workers’ safety motivation. However, understanding of the cognitive factors that contribute to safety motivation is lacking. In this study, we examine internal safety locus of control and safety self-efficacy as mediators of the effects of a safety intervention on safety motivation. In 2016, 464 students from eight vocational schools participated in a school-based cluster randomized, controlled intervention study conducted in Finland. In the multiple mediation model investigated using structural equation modeli…
We need more replication research – A case for test-retest reliability
2017
Following debates in psychology on the importance of replication research, we have also started to see pleas for a more prominent role for replication research in medical education. To enable replication research, it is of paramount importance to carefully study the reliability of the instruments we use. Cronbach’s alpha has been the most widely used estimator of reliability in the field of medical education, notably as some kind of quality label of test or questionnaire scores based on multiple items or of the reliability of assessment across exam stations. However, as this narrative review outlines, Cronbach’s alpha or alternative reliability statistics may complement but not replace psyc…
Acceptance and validity of the methods used to implement a competency based medical education programme in an Intensive Care Department of a teaching…
2021
Abstract Objectives 1. To determine the satisfaction of tutors and residents with a specific methodology used to implement CoBaTrICE. 2. To determine the reliability and validity of the global rating scales designed ad hoc to assess the performance of the residents for training purposes. Design Prospective cohort study. Participants All the residents and tutors of the ICU Department of the Hospital Universitario y Politecnico la Fe de Valencia. Intervention CoBaTrICE implementation started in March 2016, it was based on: (1) Training the tutors in feedback techniques; (2) Performing multiple objective and structured work based assessments to achieve the competences of the program; and (3) T…
Are Traffic Announcements Really Effective? A Systematic Review of Evaluations of Crash-Prevention Communication Campaigns
2021
Communication campaigns are commonly used in the traffic and road safety sector to raise public awareness of the importance of avoiding risky road user attitudes and behaviors. Surprisingly few of these communication campaigns evaluate their effectiveness in a formal and comprehensive manner. The core aim of the present systematic review is to identify the type of studies that evaluate the effectiveness of campaigns in this sector, in order to identify and contrast their main findings. This systematic review followed the PRISMA methodology, by means of which the relevant articles based on the search term were identified. A total of 613 indexed articles were filtered, and a final set of 27 a…
Intra- and Inter-Rater Reliability of Strength Measurements Using a Pull Hand-Held Dynamometer Fixed to the Examiner's Body and Comparison with Push …
2021
Hand held dynamometers (HHDs) are the most used method to measure strength in clinical sitting. There are two methods to realize the assessment: pull and push. The purpose of the present study was to evaluate the intra- and inter-rater reliability of a new measurement modality for pull HHD and to compare the inter-rater reliability and agreement of the measurements. Forty healthy subjects were evaluated by two assessors with different body composition and manual strength. Fifteen isometric tests were performed in two sessions with a one-week interval between them. Reliability was examined using the intra-class correlation (ICC) and the standard error of measurement (SEM). Agreement between …
Impact of graphitic carbon nitride nanosheets in mixed- matrix membranes for removal of heavy metals from water
2021
International audience; Removal of heavy metal ions from water is being a challenge and Polysulfone (PSf) membranes have shown great potential to remove them from contaminated solutions. In this work, the introduction of Graphitic carbon nitride nanosheets (g-C3N4) into PSf membranes was implemented to improve the permeability and separation performance of PSf membranes. g-C3N4 was incorporated into the membrane matrix via nonsolvent induced phase inversion method. The prepared mixed matrix membranes showed enhanced performances towards water filtration. The incorporation of g-C3N4 into the membrane matrix caused an increase in the desired physicochemical properties like hydrophilicity and …
Preliminary evaluation of biopolymers production by mixed microbial culture from citrus wastewater in a MBR system using respirometric techniques
2021
Abstract This preliminary study was aimed at evaluating the feasibility to produce biopolymers (BP) from citrus wastewater by mixed microbial culture in an anaerobic/aerobic membrane bioreactor (A/O-MBR). The activated sludge of the A/O-MBR was successfully enriched in microorganisms having a good capacity in producing intracellular biopolymers. The production of BP was found to be about 0.55 mgCOD mgCOD−1 using pure acetate at a concentration of 1000 mgCOD L−1. When using fermented wastewater, the conversion of acetate into BP product was 0.56 mgCOD mgCOD−1 in the test performed with C/N equal to 1000:1, whereas it was only 0.12 mgCOD mgCOD−1 in the test with C/N of 100:5. The results achi…