基于单一聚类方法的航空器相撞HFACS诱发模式分析

为了有效防控航空器相撞事故的发生,保证航空系统安全、有序和高效运行,提出一种基于单一聚类过程的人为因素分析分类系统(HFACS)诱发模式分析方法。在该方法中,首先,根据航空器相撞的具体特点建立了HFACS。然后,利用HFACS对发生的航空器相撞事故/事故征候进行量化,构建历史信息的数据表。最后,采用单一聚类方法对得到的数据表进行诱发模式分析,识别出重要的诱发模式及模式中包含的重要影响因素,并据此提出防相撞的管控措施。实例分析表明,所提出方法的实现过程简便,定性定量结合,形式易于理解,分析结果也更加贴近实际,对于提升防相撞的管理和决策水平,防范航空器相撞及减少造成的损失具有重要的实用价值。     

飞机发动机关键系统智能故障诊断方法

飞机发动机是一个非常复杂的大系统,由于其结构复杂,工作环境恶劣,对其关键系统的故障进行准确诊断始终是困扰业界的技术瓶颈之一。提出了采用EMD小波阈值降噪与主元分析相结合的方法,对飞机发动机气路系统故障诊断进行了深入研究。针对某型真实飞机发动机进行测试试验采集的气路多参量数据,首先采用经验模态分解(Empirical Mode Decomposition,EMD)对气路系统各参量信号进行EMD分解,然后采用软阈值函数对其进行降噪,并进行信号重构,从而可得到飞机发动机气路工作状态有效数据。在此基础上,设计了飞机发动机气路系统主元分析故障诊断模型,并结合预处理得到的飞机发动机气路有效数据,运用所设计的主元分析故障诊断模型对飞机发动机进行故障诊断技术研究。研究结果表明,所提出的方法能够很好地诊断出飞机发动机气路系统实际运行时所出现的故障,具有重要的实际应用价值,并有广泛的应用前景。     

军用飞机改进改型研制费用的参数估算法

首先分析并建立了军用飞机改进改型研制的费用分解结构,阐明了与新研飞机在各分项费用上的差别。基于当量工程的概念提出了用减缩系数来估算改进改型研制的费用修正和各分项费用的减缩系数的估计方法,结合现有成熟的参数估算模型建立了相应的改进改型研制的费用估算模型。最后,以某型飞机的改型研制费用为例进行了实例分析,结果表明方法与模型具有较好的有效性和实用性。     

Revenue management with aircraft reassignment flexibility

A well‐studied problem in airline revenue management is the optimal allocation of seat inventory among different fare‐classes, given a capacity for the flight and a demand distribution for each class. In practice, capacity on a flight does not have to be fixed; airlines can exercise some flexibility on the supply side by swapping aircraft of different capacities between flights as partial booking information is gathered. This provides the airline with the capability to more effectively match their supply and demand. In this paper, we study the seat inventory control problem considering the aircraft swapping option. For theoretical and practical purposes, we restrict our attention to the class of booking limit policies. Our analytical results demonstrate that booking limits considering the swapping option can be considerably different from those under fixed capacity. We also show that principles on the relationship between the optimal booking limits and demand characteristics (size and risk) developed for the fixed‐capacity problem no longer hold when swapping is an option. We develop new principles and insights on how demand characteristics affect the optimal booking limits under the swapping possibility. We also develop an easy to implement heuristic for determining the booking limits under the swapping option and show, through a numerical study, that the heuristic generates revenues close to those under the optimal booking limits. © 2011 Wiley Periodicals, Inc. Naval Research Logistics, 2011     

邻域加强的并行子空间优化过程

针对基于响应面的并行子空间优化(CSSo-RS)过程的不足,提出了基于邻域加强的改进CSSO-RS优化过程.其主要思路是在子空间优化后,在得到的最优解附近进行全部变量的优化,以更好地协调系统级优化与子空间优化.用经典测试函数及通用航空飞机参数优化问题对该算法进行测试,测试结果表明该算法使CSSO-RS优化效率得到较大的...     

基于LS-SVM的飞机保障性预测评估建模

针对飞机保障性预测评估建模难的问题,基于统计学习理论,采用LS-SVM方法,建立了飞机保障性的预测模型。仿真试验结果表明,LS-SVM具有很高的建模精度和较强的泛化能力,从而验证了该方法的有效性和先进性。     

Research communication security in the 90s: A view from the UK

This paper develops a methodology for measuring the capital value of military assets in monetary terms. We distinguish between two military capital measures. One measure, called the value of military capital (services) summarizes the value of military defense assets during a particular year. A comparison of the capital‐services value of U.S. and Soviet tactical combat aircraft is provided for the period 1970–1984.

One feature of the capital‐services measure that makes it particularly interesting is that its size can be compared with such military expenditures as operating and support. While these latter expenditures reflect the readiness of a defense establishment, the relevant capital‐services measure reflects force structure and modernization.

A second measure, called the value of military capital (wealth), summarizes the military benefits obtained from defense assets over the remainder of their service lives. This measure depreciates the capital as it ages, and is useful for comparing military wealth with other types of wealth in the economy. We provide this measure for the U.S. military capital stock for 1925–1984.     

Investigating optimal replacement of aging air force systems

An availability‐oriented approach has been developed to decide when to replace an aging system. For an existing system, it is optimal to operate another year if and only if the incremental cost per available year is less than the lifetime average cost per available year of a new aircraft. We illustrate our approach using United States Air Force KC‐135 tanker data. In demonstrating our approach, we find it will be optimal to replace the KC‐135 by the end of the decade.     

针对隐身突防的海上编队雷达网建模与仿真

雷达组网是实现反隐身的一种有效技术。通过模拟隐身飞机在有无干扰情况下从空中和低空突防,对海上编队雷达网的对抗过程进行仿真,经过认知模型对探测效能的解算,得出优化的舰艇部署阵位。仿真结果表明所建立模型的可行性和正确性,并可为舰艇指挥员综合决策提供科学依据。     

基于作战协同航母编队兵力配置方法

从作战协同的角度研究航母编队兵力配置问题。首先介绍了航母编队兵力配置空间协同方法,即层次协同、海域协同、空域协同、方向协同、高度协同等方法。根据基于航母编队对空作战、对海作战、对岸作战和对潜作战4种基本作战样式下,探讨了协同因素对兵力配置的影响与约束,并提出了相应的原则与思路,进一步完善航母编队兵力配置理论。