邻域灰度差加权的模糊C均值聚类图像分割算法

模糊C均值(FCM)算法用于灰度图像分割是一种非监督模糊聚类后再标定的过程,适合灰度图像中存在着模糊和不确定性的特点.但是这种算法没有考虑到样本空间中不同的样本点对分类的贡献不同,因此分割效果不理想.提出了邻域灰度差加权的模糊C均值聚类算法,实验结果表明,该算法不仅取得了很好的分割效果,而且加快了算法的收敛速度,从而满足了图像分割的有效性、实时性的要求.     

基于随机Petri网的装备抢救抢修保障模型

通过建立一个基本的装备抢救抢修Petri网模型,把Petri网建模思想引入战时装备抢救抢修保障模型中,将实际系统中的实体和活动映射为模型系统中的库所和变迁,将装备抢救抢修保障排队论模型用随机Petri网进行描述。构建了一个完整的装甲团装备抢救抢修随机Petri网模型,利用软件包SPNP6.0对其进行模拟运行,通过对模型仿真数据的分析为装备保障的方案制定提供决策依据。     

反潜编队应召搜索能力计算及效果评估

本文在分析反潜编队应召搜索特点的基础上,对应召搜索能力进行了必要的战术计算,对应召搜索的效果进行了评估,为实际反潜作战中提高对潜搜索的效果提供了可靠的依据。     

概率条件下雷区范围估计研究

为更正现有雷区范围估计算法因搜扫率处置不当而存在的矛盾与不足,研究了搜扫率条件下的雷区范围估计问题。分不规则雷区和规则雷线两种情况,依据极大似然估计的原理,推导出搜扫率条件下的雷区范围估计算法,并对改进算法与现有算法进行了分析比较和仿真示例验证。分析和示例表明新算法克服了现有算法的缺陷,能够更符合实际地解决雷区范围估计问题。     

关于半鞅向量随机积分的一个注

建立了半鞅向量随机积分的一个结果,能方便处理可料过程在向量随机积分意义下对半鞅的分解随可料过程不同而不同的问题.作为其应用,给出了有关文献中定理的简洁证明.并利用其思想,得到了半鞅向量随机积分的一个重要性质.     

Detection of a Markovian target with optimization of the search efforts under generalized linear constraints

This paper deals with search for a target following a Markovian movement or a conditionally deterministic motion. The problem is to allocate the search efforts, when search resources renew with generalized linear constraints. The model obtained is extended to resource mixing management. New optimality equations of de Guenin's style are obtained. Practically, the problem is solved by using an algorithm derived from the FAB method. © 2002 Wiley Periodicals, Inc. Naval Research Logistics 49: 117–142, 2002; DOI 10.1002/nav.10009     

Inventory control under substitutable demand: A stochastic game application

Substitutable product inventory problem is analyzed using the concepts of stochastic game theory. It is assumed that there are two substitutable products that are sold by different retailers and the demand for each product is random. Game theoretic nature of this problem is the result of substitution between products. Since retailers compete for the substitutable demand, ordering decision of each retailer depends on the ordering decision of the other retailer. Under the discounted payoff criterion, this problem is formulated as a two‐person nonzero‐sum stochastic game. In the case of linear ordering cost, it is shown that there exists a Nash equilibrium characterized by a pair of stationary base stock strategies for the infinite horizon problem. This is the unique Nash equilibrium within the class of stationary base stock strategies. © 2002 Wiley Periodicals, Inc. Naval Research Logistics 49: 359–375, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/nav.10018     

加权随机模拟的时变可靠性分析方法

针对结构时变可靠性的随机模拟分析方法计算代价大的问题,在极值方法的基础上提出基于加权随机模拟的时变可靠性分析策略.时变可靠性分析需要计算在不同时间处的失效概率,通常需要进行多次可靠性分析,计算代价巨大.所提方法通过对常规静态可靠性的随机模拟方法进行改进拓展,运用加权策略分别发展了加权蒙特卡洛法和加权重要抽样法,使之能够...     

Reliability inference for field conditions from accelerated degradation testing

Accelerated degradation testing (ADT) is usually conducted under deterministic stresses such as constant‐stress, step‐stress, and cyclic‐stress. Based on ADT data, an ADT model is developed to predict reliability under normal (field) operating conditions. In engineering applications, the “standard” approach for reliability prediction assumes that the normal operating conditions are deterministic or simply uses the mean values of the stresses while ignoring their variability. Such an approach may lead to significant prediction errors. In this paper, we extend an ADT model obtained from constant‐stress ADT experiments to predict field reliability by considering the stress variations. A case study is provided to demonstrate the proposed statistical inference procedure. The accuracy of the procedure is verified by simulation using various distributions of field stresses. © 2006 Wiley Periodicals, Inc. Naval Research Logistics, 2006.     

防御矩阵满足乘法交换律的证明

在使用马尔柯夫链分析多层防御系统的防御效用值时,发现防御矩阵是否满足乘法交换律将关系到多层防御系统变换部署后的防御效用值,因此有必要对防御矩阵是否满足乘法交换律进行证明。首先介绍了防御矩阵的概念、物理意义、重要性质及计算方法,分析了防御矩阵满足乘法交换律的重要意义,最后综合运用数学归纳法和随机矩阵性质证明了防御矩阵满足乘法交换律的事实,此结论无论对于多层防御系统的防御效用值研究还是矩阵理论研究都有一定的指导作用。