SUMMARY Interval-censored life-history data arise when the events of interest are only detectable at periodic assessments. When interest lies in the occurrence of two such events, bivariate-interval censored event time data are obtained. We describe how to fit a four-state Markov model useful for characterizing the association between two interval-censored event times when the assessment times ...

This paper deals with the condition-based maintenance of single-unit systems which are subject to the competing and dependent failures due deterioration and traumatic shock events. The main aim is to provide a model to assess the value of condition monitoring information for the maintenance decision-making. A condition-based periodic inspection/replacement policy is developed and compared with ...

Historically, wind machines were used for grinding grain in Persia as early as 200 BC. Wind turbines have been in use since 1941 when the world’s first megawatt-size wind turbine was connected to the local electrical distribution system in Vermont, USA. The function of a modern power-generating wind turbine is to generate high quality, network frequency electricity. To give an example of the sc...

We report on the structural investigation of self-organized periodic microstructures (ripples) generated in Si(100) targets after multishot irradiation by approximately 100-fs to 800-nm laser pulses at intensities near the single shot ablation threshold. Inspection by surface sensitive microscopy, e.g., atomic force microscopy (AFM) or scanning electron microscopy (SEM), and conventional and hi...

Aircraft structures require periodic and scheduled inspection and maintenance operations due to their special operating conditions and the principles of design employed to develop them. Therefore, structural health monitoring has a great potential to reduce the costs related to these operations. Optical fiber sensors applied to the monitoring of aircraft structures provide some advantages over ...

Abstract. It is well-known that non-periodic boundary conditions reduce considerably the overall accuracy of an approximating scheme. In previous papers the present authors have studied a fourth-order compact scheme for the one-dimensional biharmonic equation. It relies on Hermitian interpolation, using functional values and Hermitian derivatives on a three-point stencil. However, the fourth-or...

Hospital sanitary microbiology laboratories perform the sanitary inspection, especially in high-risk wards, control hospital flora contamination, which is often multiresistant, perform the periodic monitoring of staff at risk and the examination of persons outside the institution. Data on chemotherapy, germs and tested samples from a sanitary microbiology laboratory revealed specific issues. Th...

In this paper, the periodic, quasi periodic and chaotic responses of rotational machines with a hexagonal centrifugal governor are studied. The external disturbance is assumed as a sinusoid effect. By using the forth order Rung-Kutta numerical integration method, bifurcation diagram, largest Lyapunov exponent and Lyapunov dimension are calculated and presented to detect the critical controlling...

Dark magnetic spots crossing the stellar disc lead to quasi-periodic brightness variations, which allow us constrain surface rotation and photometric activity. The current work is second of this series (Santos et al. 2019; Paper I), where we analyze Kepler long-cadence data 132,921 main-sequence F G stars late subgiant stars. Rotation-period candidates are obtained by combining wavelet analysis...

The process of vehicle inspection in the United Arab Emirates has been investigated in this study using multiple decision-making criteria. The objective was to assess the current situation and set out recommendations to improve vehicle inspection procedure. Inspected mechanical and environmental parameters have been compared among different inspection centers in the country. The assessment incl...