Aiming at the problems of large equipment maintenance support tasks,limited support resources,extensive maintenance scheduling organization,and low support benefits.An equipment maintenance cost model,accurately calculates the equipment maintenance cost is established by using the activity-based costing method to analyze the relationships between equipment maintenance resource input and benefits,and also a multi-objective equipment maintenance optimization model is established,which is with the goal of the largest number of repaired equipment and the lowest average maintenance cost.Aiming at the characteristics of multiple model parameters and complex calculations,an improved hybrid nested particle swarm algorithm is designed based on a comprehensive use of particle swarm algorithm and genetic algorithm.A maintenance organization is taken as an example to carry out simulation calculations to verify the model and algorithm.The model and algorithm provide a certain theoretical basis for equipment maintenance decision-making.

Many kinds of UAVs were used throughout the conflict in Nagorno-Karabakh in 2020.The UAVs strike a lot of tactical targets,and play an important role in effecting on battlefield situation.By analyzing the main UAVs' performance of Azerbaijan,the operational mode and typical attack and defense cases are analyzed.The suggestion for capability demand on ground-to-air anti-UAVs is provided based on the reason of failure in Armenia anti-air operation.This conclusion supports development and operation of ground-to-air anti-UAVs equipment.