Preventing broken-rail-caused derailments is a high priority for the rail industry and government. The current practice is to periodically inspect rails using non-destructive technologies such as ultrasonic rail inspection. Determining the optimal inspection frequency is a critical decision in railway infrastructure management. The objective of this paper is to develop an analytical framework t...

Optimizing inspection and maintenance (I&M) plans for a large deteriorating structure is computationally challenging task, in particular if one considers interdependences among its components. This due to the sheer number of possible decision alternatives over lifetime uncertainty surrounding deterioration processes, structural performance outcomes actions. To address this challenge, Luque Stra...

In this paper, two economic production quantity (EPQ) models are proposed for deteriorating/imperfect items with rework process. The production process is imperfect, and imperfect quality items are reworked to become serviceable. At the same time, the remaining good quality items may deteriorate. The inspection of deteriorated items is also imperfect, so that deteriorated items may be sold to c...

The paper presents a sampling-inspection strategy for the evaluation of time-dependent reliability of deteriorating systems, where the deterioration is assumed to initiate at random times and at random locations. After initiation, defects are weakening the system’s resistance. The system becomes unacceptable when at least one defect reaches a critical depth. The defects are assumed to initiate ...

Tax evasion has always been an important topic to tax theory researchers and the department of government. However, existing research results are confined to the unilateral action of taxpayers, neglect the interaction between the tax declaration and taxation inspection. This paper, from an optimal tax administration perspective, builds a general equilibrium model, in which, taxation inspection ...

Processing speed is an important contributor to working memory performance and fluid intelligence in young children. Myelinated white matter plays a central role in brain messaging, and likely mediates processing speed, but little is known about the relationship between myelination and processing speed in young children. In the present study, processing speed was measured through inspection tim...

A “phantom stockout” is a retail stockout phenomenon caused either by inventory shrinkage or by shelf execution failure. Unlike the conventional stockout which can be corrected by inventory replenishment, a phantom stockout persists and requires human interventions. In this paper, we propose two partially-observable Markov decision models: one for the shrinkage problem and the other for the she...