There is a long tradition in population genetics of exploring the maintenance of variation under migration-selection balance using deterministic models that assume infinite population size. With finite population size, stochastic dynamics can greatly reduce the potential for the maintenance of polymorphism, but this has yet to be explored in detail. Here, classical two-patch models are extended...

The present paper aims to investigate the effects of modularity and the layout of subsystems and parts of a complex system on its maintainability. For this purpose, four objective functions have been considered simultaneously: I) maximizing the level of accordance between system design and optimum modularity design,II) maximizing the level of accessibility and the maintenance space required,III...

utilizing the gathered failure data and failure interval data from tabas coal mine in two years, this paper discusses the reliability of powered supports. the data sets were investigated using statistical procedures and in two levels: the existence of trend and serial correlation. the results show that the powered supports follow the gamma reliability function. the reliability of the machine de...

introduction: lipomas of the larynx are very rare benign lesions; macroscopically, they resemble retention cysts, so their diagnosis is usually made after surgery.   case report: a rare case of pediatric paraglottic space lipoma in an 11-year-old boy is explained. the mass was mobile, soft, without fluctuation or pulsation. ct scan revealed a 5.7 cm cervical fat density with regional lymphadeno...

This paper presents a maintenance optimisation method for a multi-state seriesparallel system considering economic dependence and state-dependent inspection intervals. The objective function considered in the paper is the average revenue per unit time calculated based on the semi-regenerative theory and the universal generating function (UGF). A new algorithm using the stochastic ordering is al...

Although critical to the conservation of white rhinoceros, captive breeding has proven challenging because of the poor and irregular reproductive health of many captive rhinos, and social interactions may play a significant role. This research investigated the social and spatial relationships of two captive groups of southern white rhinoceros (Ceratotherium simum simum) by examining the frequen...

AbstrAct This chapter surveys the maintenance of frequent patterns in transaction datasets. It is written to be accessible to researchers familiar with the field of frequent pattern mining. The frequent pattern maintenance problem is summarized with a study on how the space of frequent patterns evolves in response to data updates. This chapter focuses on incremental and decremental maintenance....