Search results for "Reliability and Quality"
showing 10 items of 386 documents
A robust calibration methodology for an On-Board Diagnostic car system
2006
New car models are now by law equipped with on-board diagnostic (OBD) systems aimed at monitoring the state of health of strategic components that ensure low levels of polluting exhaust emissions. During development phases, for each new car model, the OBD system must be finely calibrated. This article presents a robust calibration methodology taking into account sources of variability mainly due to production process, operating, and environmental conditions. The methodology enables us to evaluate the false alarm and failure to detect risks intrinsically related to the adopted calibration. An application concerning an upstream oxygen sensor monitored by the OBD is presented.
Frequency mapping in dynamic light emission with wavelet transform
2013
International audience; Dynamic photon emission microscopy is an e cient tool to analyse today's integrated circuit. Nevertheless, the reduction of transistor's dimensions leads to more complex acquisitions where many spots can be seen. A frequency characterization of the whole acquired area can help to have a better understanding of it. With that purpose in mind, a new methodology to draw frequency mapping of dynamic light emission acquisition is reported. It is fully automated and based on wavelet transform and autocorrelation function. Regarding the possible use in an industrial context, the suggested method can help to localize abnormal emission activity and it gives some perspectives o…
Profiling Safety Behaviors: Exploration of the Sociocognitive Variables that Best Discriminate Between Different Behavioral Patterns
2012
This study combines contributions from both safety climate literature and prominent social influence theories. It was developed to identify the combination of sociocognitive variables that differentiate between different profiles of safety behaviors. This empirical approach has hardly been explored in the literature on behavioral aspects related to safety. The research setting for this study was a transportation company (N= 356). The results of discriminant analysis showed that different combinations of dispositional and situational influences may lead to diverse profiles of compliance and proactive safety behaviors. Perceived behavioral control was revealed to be the variable that best dif…
Safety climate responses and the perceived risk of accidents in the construction industry
2008
The usefulness of safety climate as a diagnostic tool ought to reside in its ability to identify detailed and precise difficulties that can be considered critical to improving safety. This feature depends on the theoretical analysis of the agents and issues that should be included in safety climate statements. Safety climate can be analysed from the point of view of the agent that performs the safety response in question, by identifying four main safety agents (organization, supervisors, co-workers and worker) and five safety climate variables: the Organizational Safety Response (OSR), the Supervisors' Safety Response (SSR), the Co-Workers' Safety Response (CSR), the Worker Safety Response …
A Robustness Approach to Reliability
2012
Reliability of products is here regarded with respect to failure avoidance rather than probability of failure. To avoid failures, we emphasize variation and suggest some powerful tools for handling failures due to variation. Thus, instead of technical calculation of probabilities from data that usually are too weak for correct results, we emphasize the statistical thinking that puts the designers focus on the critical product functions. Making the design insensitive to unavoidable variation is called robust design and is handled by (i) identification and classification of variation, (ii) design of experiments to find robust solutions, and (iii) statistically based estimations of proper safe…
A nonlinear dynamical approach to the path correction of multi-steering articulated vehicles
2020
When designing articulated tractor-trailer systems, engineers should take care to contrast some undesired phenomena associated with the lateral dynamics: the path off-tracking, namely the trajector...
A predictive maintenance policy with imperfect monitoring
2010
For many systems,failure is a very dangerous or costly event. To reduce the occurrence of this event,it is necessary to implement a preventive maintenance policy to replace the critical elements before failure.Since elements do not often exhibit incipient faults, they are replaced before a complete exploiting of their useful life.To conjugate the objective of exploiting elements for almost all their useful life with the objective to avoid failure,condition based and,more recently,predictive maintenance policies have been proposed.This paper deals with this topic and proposes a procedure for the computation of the maintenance time that minimizes the global maintenance cost.By adopting a stoc…
On the sway stability improvement of car–caravan systems by articulated connections
2015
The present analysis is addressed to some promising connection arrangements between the towing vehicles and the towed trailers, where the two units are linked by four-bar isosceles trapeziums in place of the conventional pintle hitch. Two types of instability, of the divergent type or the oscillating type, may be analysed by the Routh–Hurwitz criterion or by the direct analysis of the characteristic equation. The constant term of this equation vanishes at the divergent instability threshold (zero of a real root), whereas the equation splits into two lower degree algebraic ‘sub-equations’ when the oscillating instability arises (pair of pure imaginary roots). A large field of geometrical con…
Strengthening Safety Compliance in Nuclear Power Operations: A Role-Based Approach
2014
Safety compliance is of paramount importance in guaranteeing the safe running of nuclear power plants. However, it depends mostly on procedures that do not always involve the safest outcomes. This article introduces an empirical model based on the organizational role theory to analyze the influence of legitimate sources of expectations (procedures formalization and leadership) on workers' compliance behaviors. The sample was composed of 495 employees from two Spanish nuclear power plants. Structural equation analysis showed that, in spite of some problematic effects of proceduralization (such as role conflict and role ambiguity), procedure formalization along with an empowering leadership s…
Stop there’s water on the road! Identifying key beliefs guiding people’s willingness to drive through flooded waterways
2016
Floods are among the most widespread of natural disasters and exposure to floodwaters increases drowning risk. A leading cause of flood related drowning deaths is driving through flooded waterways. Drawing on the Theory of Planned Behaviour, a two-phased research program was conducted. Phase 1 (N = 25; Mage = 32.38, SD = 11.46) identified common beliefs about driving through a flooded waterway. Phase 2 (N = 174; Mage = 27.43, SD = 10.76) adopted a cross-sectional design to examine the belief predictors of drivers' willingness to drive through a flooded waterway. Given differences in consequences due to the depth of water, scenarios of low (road covered in 20 cm of water) and high (road cove…