The government of the Republic Korea has set minimum service level bridges as Grade B and defined risk management higher than 95 percent. To achieve this goal, it is necessary to understand deterioration process deficiencies for bridges, these characteristics should be reflected in strategy budget investment plan. end, study developed models according bridge ages define heterogeneous aging brid...

This paper deals with an integrated model for the joint determination of both economic production quantity (EPQ) and level of preventive maintenance (PM) for an imperfect production process. This process has a general deterioration distribution with increasing hazard rate. The effect of PM activities on the deterioration pattern of the process is modeled using the imperfect maintenance concept....

Since new drinking water regulations were implemented in England and Wales in 2000, cryptosporidiosis has been significantly reduced in the first half of the year but not in the second. We estimate an annual reduction in disease of 905 reported cases and approximately 6,700 total cases.

This longitudinal study examined the effect of the birth of the 1st child on relationship functioning using data from 218 couples (436 individuals) over the course of the first 8 years of marriage. Compared with prebirth levels and trajectories, parents showed sudden deterioration following birth on observed and self-reported measures of positive and negative aspects of relationship functioning...

Asexual species accumulate deleterious mutations through an irreversible process known as Muller's ratchet. Attempts to quantify the rate of the ratchet have ignored the role of temporal environmental heterogeneity even though it is common in nature and has the potential to affect overall ratchet rate. Here we examine Muller's ratchet in the context of conditional neutrality (i.e., mutations th...