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...

This paper presents a review and experimental results on the major benchmarking functions used for performance control of Genetic Algorithms (GAs). Parameters considered include the eect of population size, crossover probability and pseudo-random number generators (PNGs). The general computational behavior of two basic GAs models, the Generational Replacement Model (GRM) and the Steady State Re...

This paper generalizes Yeh Lam’s shock model for renewal shock arrivals and random threshold. Several interesting statistical measures are explicitly obtained. A few special cases and an optimal replacement problem are also discussed. Keywords— shock model, optimal replacement, random threshold, shocks.

the continuous improvement of eaf performance is crucial for the increase in productivity and cost effectiveness and to render an environmental friendly process. rhi supports these targets by providing a diverse range of refractory and process solutions. chemical energy in practical operation by injection of gaseous media like oxygen and natural gas, and solid materials like carbon have become ...

This paper presents experimental results on the major benchmarking functions used for performance evaluation of Genetic Algorithms (GAs). Parameters considered include the e€ect of population size, crossover probability, mutation rate and pseudorandom generator. The general computational behavior of two basic GAs models, the Generational Replacement Model (GRM) and the Steady State Replacement ...

juvenile idiopathic arthritis is the leading cause of hip replacement in young children. however, arthroplasty in this population is challenging with several concerns about quality of the growing bone, young age for revision surgery, and difficulties in potential several revisions. in this study we introduce a case of a 12-year old who is one of the youngest patients to undergo revision hip art...

background: natural endometrium in frozen-thawed embryo transfer (fet) may have some benefits upon implantation in patients with repeated implantation failure (rif). it might be due to possible differences between natural and stimulated endometrial growth factors and cytokins secretions. objective: the objective of this study was to compare the pregnancy rate of fet on modified natural cycle ve...

Graphical belief networks, including Bayes nets and influence diagrams, can be represented with directed hypergraphs. Each directed hyperedge corresponds to a factor of the joint distribution of all variables in the model. A hyperedge replacement grammar is a collection of rules for replacing hyperedges with hypergraphs. A hyperedge replacement grammar for graphical belief networks defines a co...

This paper explores a reliability based heuristic mathematical model for basic and classical age replacement policy. Using new model, optimal preventive age replacement policy is determined to maximize system reliability. For special systems having exponential density function with constant hazard function, a different simple decision-making model is proposed. A case study of two industrial mac...

 Abstract Background: Esophageal replacement is indicated in certain circumstances including long gap esophageal atresia, severe strictures due to gastro-esophageal reflux (GER) and caustic burns. We analyzed our results of 18 patients who underwent esophageal replacement in our university hospital. Methods: We reviewed esophageal replacements carried out in our department between June 1996 and...