Search results for "reliability"
showing 10 items of 1563 documents
Excessive Deflection in Long-Span Timber Beams of a Historical Building in the South of Italy: Analysis and Retrofitting Design
2020
AbstractIn 2018, under service conditions, excessive deflections were observed in the long-span timber beams of the first floor of the former Sant’Elisabetta Monastery in Palermo (Italy). The build...
The power of empowering team leadership over time: A multi-wave longitudinal study in nuclear power plants
2021
Abstract Team attitudes in critical infrastructures are essential to achieving reliable operations despite internal and external challenges, and empowering team leadership (ETL) may be an important precursor of these attitudes. The present study aimed to test whether ETL was related to teams’ satisfaction trajectories, measured as changes in job satisfaction and safety satisfaction at three time points. Hypotheses were tested in a sample of 48 teams from two Spanish nuclear facilities in three different waves (2008, 2011, and 2014). Growth Modeling using hierarchical linear models with SPSS 20.0 revealed that ETL was positively related to initial levels of teams’ job and safety satisfaction…
Comparison of different segmentation approaches without using gold standard. Application to the estimation of the left ventricle ejection fraction fr…
2011
International audience; A statistical method is proposed to compare several estimates of a relevant clinical parameter when no gold standard is available. The method is illustrated by considering the left ventricle ejection fraction derived from cardiac magnetic resonance images and computed using seven approaches with different degrees of automation. The proposed method did not use any a priori regarding with the reliability of each method and its degree of automation. The results showed that the most accurate estimates of the ejection fraction were obtained using manual segmentations, followed by the semiautomatic methods, while the methods with the least user input yielded the least accu…
The EORTC computer-adaptive tests measuring physical functioning and fatigue exhibited high levels of measurement precision and efficiency
2013
Objectives: The European Organisation for Research and Treatment of Cancer (EORTC) Quality of Life Group is developing a computer-adaptive test (CAT) version of the EORTC Quality of Life Questionnaire (QLQ-C30). We evaluated the measurement properties of the CAT versions of physical functioning (PF) and fatigue (FA) and compared these with the corresponding QLQ-C30 scales. Study Design and Setting: Based on international samples of more than 1,000 cancer patients, we simulated CAT administration of varying numbers of items and compared the resulting scores with those based on all items in the respective item pools. Furthermore, the relative validity (RV) of CATs was compared with that of th…
Non linear and linearized combination coefficients for modal pushover analysis
2017
Current design practice and seismic codes tend to assess seismic demand of buildings by Non linear Static Analysis (NSA), based on the evaluation of the pushover curve. Earlier non-linear static analysis procedure estimate the response peak value by evaluating the push-over curve adopting a distribution of invariant forces proportional to the fundamental vibration mode. In order to include the effect of higher modes several multimodal push-over analysis procedures were proposed in literature. In In the most famous of these, namely Modal Pushover Analysis (MPA), nodal response peak values are obtained by combination of "modal" responses by the traditional SRSS or CQC methods: the use of the …
Relevance of Tool Life Testing for Tool Replacement Strategies
1986
Several analytical and simulation models have been proposed in order to select the optimal tool replacement strategies both in single and multi-tool machining operations. All of these models, however, assume as known the probability density function that describes the stochastic behaviour of tool life. The costly efforts required in order to achieve an accurate estimate of the p.d.f. limits the use in the shop practice of the above models.
The Shaping of Flux Density at the Air Gap of Small DC Motors with Different Permanent-Magnet Poles
1995
Design, operation and reliability of permanent-magnet DC micromotors are highly dependent of the magnet employed, i.e. of its demagnetization curve, type of magnetization (either radial or tangential), size and position within the micromotor as well as of its shape.
Returns to Schooling in Spain: How Reliable are Instrumental Variable Estimates?
2002
This paper studies the ordinary least–squares (OLS) and instrumental variable (IV) estimates of the returns to schooling for male workers in Spain. OLS estimates are often biased due to the endogeneity of schooling, measurement errors or omitted variables. Proper IV estimates correct this bias. The reliability of family background, natural experiments (based on changes in the education system and season of birth) and the availability of a college in the province is checked using Spanish data. The results suggest that background and college availability are valid instruments and that the IV estimates of the returns to schooling are higher than OLS estimates. These results are in line with th…
Microcirculatory Assessment of Arterial Below-Knee Stumps: Near-Infrared Spectroscopy Versus Transcutaneous Oxygen Tension—A Preliminary Study in Pro…
2017
International audience; Objective: To examine metrologic properties of near-infrared spectroscopy (NIRS) versus transcutaneous oxygen tension (TcPO2) for micro-circulatory assessment of vascular transtibial stumps at the stabilized period of prosthesis fitting, as a preliminary step before exploring its ability to predict stump healing, considering the previously identified limits of TcPO2 (borderline area between 15 and 35mmHg).Design: Prospective single-center observational study.Setting: University-based rehabilitation center.Participants: Individuals with unilateral transtibial amputation for peripheral artery disease, at the definitive stage of prosthesis fitting, able to perform a 2-m…
Development and psychometric properties of an instrument for the Assessment of Sexual Behaviour and Knowledge of people with Intellectual Disability
2020
Background This paper presents psychometric properties of an instrument for the Assessment of Sexual Behaviour and Knowledge of people with Intellectual Disability (ASBKID), other‐reported by professionals who are in daily contact with them. Methods and procedures Assessments of 236 individuals with intellectual disability were obtained from 100 professionals. Results Confirmatory factor analysis revealed a four‐factor structure: concern about the user's inappropriate or uninhibited sexual behaviour; perception of the user's knowledge about privacy and social norms; perception of the user's knowledge about sexuality; and concerns about the user's sexuality. A multi‐group CFA was also conduc…