A predictive-maintenance structure for a gradually deteriorating single-unit system (continuous time/continuous state) is presented in this paper. The proposed decision model enables optimal inspection and replacement decision in order to balance the cost engaged by failure and unavailability on an infinite horizon. Two maintenance decision variables are considered: the preventive replacement t...

To prevent members in steel bridges from fatigue failure, one usually needs to perform frequent periodic bridge inspections and employ detailed inspection methods. This is especially true for fracture-critical members or details. Carrying out these inspections puts a large burden on a transportation agency’s bridge maintenance budget. A systematic reliability-based method for inspection schedul...

There have been many analyses made of models for equipment inspection, i. e ., where a system may suffer a bre.akdowfl, ~ut such an event is only discovered by an inspection. Most analyses as· ~ume t~at the tIme to failure follows a negative exponential law which implies that only periodic mspectlOn programs need b~ considered. Another model which has been analyzed by Barlow, Hunter, and Prosch...

A two-dimensional (2-D) convolution mask is proposed for detecting the location of irregularities and defects in a periodic two-dimensional signal or image. In this approach, defects on a 2-D test image is automatically filtered out by a 2-D convolution mask implementing the spatial filter. This approach is reliable and computationally efficient. Besides, unlike the traditional die-to-die appro...

One of the most crucial elements of each country is electricity distribution networks (EDN). Awareness of accidents in EDN could be very important in the conservation and utilization of them. The accurate and periodic inspections can provide a good service to subscribers. The goal of this project is to fabricate a quad rotor, which can do an accurate and a periodic inspection. The design and im...

Pulsed eddy current inspection techniques were derived from the conventional eddy current testing technology, based on the fundamental principle of an eddy current coil, but using periodic ultrasound pulses. The authors first introduce the principle of pulsed eddy current inspection and some experimental measurement results using pulsed eddy current equipment. This technology can be applied to ...

We study an inspection and replacement policy for a system when maintenance actions are executed at times or “visits” with fixed, periodic schedule. Then, the novel focus of paper is not to schedule but what known times. Violations (defaults) may occur because time resource limited. The model motivated by typically used high-value, engineered systems e.g. windfarms, transportation systems, manu...