New Approach to Calculate the Unavailability of Identical Spares in Cold Spare Configuration

Cold spare is the most common configuration amongst the three types of configuration for systems used on board and for power generation systems. A new approach to calculate the unavailability of systems composed of identical spares in cold spare configuration was proposed in this study. Instead of using the spare gate of dynamic fault tree( DFT) and the Markov analysis,AND gate of static fault tree used for calculating the unavailability of cold spare systems was proposed in this paper. By using this approach,unavailability of identical cold spare systems composed of nonrepairable spare components can be calculated exactly and systems composed of both repairable and nonreparable identical spare components can be estimated without building large Markov state diagram.     

基于实船监测数据的定航线船舶智能航速优化

针对固定航线船舶,以实船监测数据为基础,建立船舶油耗模型,结合船舶航线信息进行航段划分.通过离散化思想,建立以航速为自变量、燃油消耗量为应变量的航速优化模型,以满足船舶航期为约束条件,采用遗传算法进行优化计算.结果显示,在选取的12个航段内,建立的船舶油耗模型误差为0.9%.通过航速优化,能够节省1.9%的油耗量,并给出各航段建议转速.优化结果可为船舶操纵辅助决策提供参考.