不完全维修下的单部件系统视情维修及更换策略

实际装备维修工程中,系统并不总能够通过维修恢复如新,并且修后工作时间和维修时间会随着系统年龄增加而分别呈现缩短和延长趋势。针对这个问题,利用连续时间马尔科夫链理论建立单部件系统在不完全维修条件下的视情维修及更换策略模型。根据马氏过程平稳状态下统计平衡原理得到状态概率方程组,并给出相应的递归求解算法。分别以系统稳态可用度最大、长期运行费用率最低以及规定可用度约束下平均故障前时间最长为目标,确定系统最优检测频率、视情维修阈值和更换策略。最后通过算例说明系统在最优维修及更换策略下达到的性能指标与系统劣化属性和维修能力水平的关系,验证了该模型的可行性。     

Novel reference range selection method in InlSAR imaging

Aiming at the reference range selection for different antennas in interferometric inverse synthetic aperture radar (InISAR) systems, this paper proposes a respective focusing (RF) method. The reference ranges for echoes of different antennas are selected respectively for RF, which is different from the traditional uniform focusing (UF) with the same reference range applied to all the antennas. First, a comparison between UF and RF for InISAR signal model considering the ranging error is given. Compared with RF, UF has an advantage in overcoming the ranging error differences between different antennas. Then the influence of ranging error upon the interferometric imaging with RF is investigated particularly, and it is found that the ranging error differences between different antennas are far smaller than the wavelength, which is advantageous to imaging. By comparing the capabilities of interferometric imaging between RF and UF, it is concluded that RF is a better choice in conquering problems such as image mismatching and phase ambiguity even with ranging errors. Simulations demonstrate the validity of the proposed method.     

江西中季种植巴西陆稻的产量性状分析

对江西中季种植南稻的试验数据进行了多角度,多方位的计算机统计分析,结果表明：中季种植巴西陆稻产量性状对产量的效应大小是：全生育期〉有效穗〉基本苗〉始穗至成熟天数〉结实率〉千粒数〉穗粒数〉播种至始穗天数。     

Modeling for UAV resource scheduling under mission synchronization

Unmanned aerial vehicle (UAV) resource scheduling means to allocate and aggregate the available UAV resources depending on the mission requirements and the battlefield situation assessment. In previous studies, the models cannot reflect the mission synchronization; the targets are treated respectively,which results in the large scale of the problem and high computational complexity. To overcome these disadvantages, a model for UAV resource scheduling under mission synchronization is proposed, which is based on single-objective non-linear integer programming. And several cooperative teams are aggregated for the target clusters from the available resources. The evaluation indices of weapon allocation are referenced in establishing the objective function and the constraints for the issue. The scales of the target clusters are considered as the constraints for the scales of the cooperative teams to make them match in scale. The functions of the intersection between the "mission time-window" and the UAV "arrival time-window" are introduced into the objective function and the constraints in order to describe the mission synchronization effectively. The results demonstrate that the proposed expanded model can meet the requirement of mission synchronization, guide the aggregation of cooperative teams for the target clusters and control the scale of the problem effectively.     

利用偏度分析建立动态检测门限的野值剔除方法

提出了一种采用动态门限检测和剔除野值的新方法。以往的单一检测门限不能可靠地清除观测数据中的全部野值 ,原因是缺少判断有无未剔除野值的识别机制。这里 ,借助于统计偏度分析建立了这种判别机制 ,从而能够有效地判断出是否存在有未被剔除的野值 ,并通过调节野值检测门限来达到彻底清除野值的目的。最后 ,还将此法推广到复数域     

适用于抗高频突发性冲击干扰的有效算法

提出了一种抗突发性冲击干扰的处理算法。该算法主要用于抑制高频雷达探测飞机目标时随机出现的冲击干扰对目标谱线产生的遮盖。由于时域海面回波一般情况下绝对占优 ,因此 ,该算法利用海杂波谱分布结构上的特点 ,通过常规的频域处理滤除海杂波谱 ,从而使滤除海杂波并反变换到时域的信号中突发冲击干扰能够占优 ,进而利用野值判别与剔除方法将幅度较突出的冲击干扰予以剔除 ,达到抑制突发冲击干扰的目的 ,使雷达在突发干扰情况下也能有效地发现和跟踪目标     

基于双库协同机制的KDD*及其软件实现

在KDD(基于数据库的知识发现 )的基础上 ,提出了KDD的开放系统—KDD 的总体结构 ;探讨了其关键技术—双库协同机制的理论基础与实现技术 ;介绍了因果关联规则的统计归纳的发掘方法。初步演示试验的结果表明 ,KDD 这类新型构造是有效与可行的。     

基于BP神经网络的房地产市场比较法价格评估

将ＢＰ神经网络理论应用于房地产市场比较法价格评估,讨论了网络结构的设计、学习算法等问题;计算实例表明,应用神经网络评估房地产价格具有方便、真实、可靠的特点。     

基于神经网络和微分对策理论的制导律

根据微分对策制导律目前面临的困境,本文尝试将神经网络引入微分对策制导律。采用ＢＰ模型,将微分对策的定量和定性分析结合起来。以导弹与飞机格斗为例,探讨其实现的可能性和优点,为将来发展基于微分对策理论的智能制导律提供了一定的思路。     

子波变换新方法

本文在理论分析子波变换物理概念的基础上,提出了一种工程上应用的新颖快速子波变换算法,即“频谱切割法”。该方法能够在电路上实现实时的快速子波变换。