C~3I系统的决策时延分析

决策是C~3I 系统的核心问题之一。用Petri 网理论研究C~3I 系统的决策问题已取得了长足的进展。根据决策过程各阶段之所需时间具有随机性及不独立性的特点,以变迁发射时间不独立的随机Petri 网作为决策时延的建模与分析工具,并给出了这种随机Petri 网模型的一般分析方法。     

On lifetimes in random environments

For a component operating in random environment, whose hazard rate is assumed to be the realization of a suitable increasing stochastic process, conditions are found such that its lifetime is increasing in likelihood ratio (ILR). For the lifetimes of two components of the same kind some comparisons based on partial stochastic orders are presented. Some applications to the case of repairable components are finally provided. © 1998 John Wiley & Sons, Inc. Naval Research Logistics 45: 365–375, 1998     

二部图的(g,f)匹配

本文证明了二部图存在(g,f)匹配和f 因子的充要条件以及有关的几个结果,并且给出了求二部图的最大(g,f)匹配、最小(g,f)匹配和最小权最大f 匹配、最小权(g,f)匹配、最大权(g,f)匹配的算法。     

基于测试码并行的同步时序电路故障模拟方法

将组合电路故障模拟的一些加速技术推广到时序电路故障模拟中,提出并实现了一个功能块级的基于测试码并行的同步时序电路故障模拟方法,对部分ISCAS89 Benchmark电路的模拟结果表明,该故障模拟方法有较好的性能.     

Experimental research on the instability propagation characteristics of liquid kerosene rotating detonation wave

In order to study the instability propagation characteristics of the liquid kerosene rotating detonation wave (RDW), a series of experimental tests were carried out on the rotating detonation combustor (RDC) with air-heater. The fuel and oxidizer are room-temperature liquid kerosene and preheated oxygen-enriched air, respectively. The experimental tests keep the equivalence ratio of 0.81 and the oxygen mass fraction of 35% unchanged, and the total mass flow rate is maintained at about 1000 g/s, changing the total temperature of the oxygen-enriched air from 620 K to 860 K. Three different types of instability were observed in the experiments: temporal and spatial instability, mode transition and re-initiation. The interaction between RDW and supply plenum may be the main reason for the fluctuations of detonation wave velocity and pressure peaks with time. Moreover, the inconsistent mixing of fuel and oxidizer at different circumferential positions is related to RDW oscillate spatially. The phenomenon of single-double-single wave transition is analyzed. During the transition, the initial RDW weakens until disappears, and the compression wave strengthens until it becomes a new RDW and propagates steadily. The increased deflagration between the detonation products and the fresh gas layer caused by excessively high temperature is one of the reasons for the RDC quenching and re-initiation.     

On gamma estimation via matrix kriging

In financial engineering, sensitivities of derivative prices (also known as the Greeks) are important quantities in risk management, and stochastic gradient estimation methods are used to estimate them given the market parameters. In practice, the surface (function) of the Greeks with respect to the underlying parameters is much more desired, because it can be used in real‐time risk management. In this paper, we consider derivatives with multiple underlying assets, and propose three stochastic kriging‐based methods, the element‐by‐element, the importance mapping, and the Cholesky decomposition, to fit the surface of the gamma matrix that can fulfill the time constraint and the precision requirement in real‐time risk management. Numerical experiments are provided to illustrate the effectiveness of the proposed methods.     

期刊载文信息中作者与读者群的互动研究——以统计信息和文献评价数据为引证

学术期刊的传播,不仅仅是纸质文本,更重要的是网络传播。其传播效益的实现更有赖于读者与作者的互动。网络传播为读者和作者提供了快速便利的互动场域。作者的学术研究首先从读者开始,没有读者,学术成果难以实现价值,学术期刊文本是作者与读者之间实现互动的桥梁。学术期刊应重视作者与读者在学术交流中的互动关系和相互影响,注重作者群的扶持与培养。     

二阶矩模糊随机过程的均方极限

给出了二阶矩模糊随机过程均方极限的两种定义,证明了这两种定义的等价性,并讨论了二阶矩模糊随机过程均方极限的性质。     

一种基于估计熵的自适应模糊滤波器及其在箭遥信号处理中的仿真应用

介绍了一种基于估计熵的自适应模糊滤波器 ,并将其应用于宽带噪声中火箭遥测速变信号的数字滤波。讨论了自适应模糊滤波算法 ,给出了应用实验结果。分析和实验表明 ,这种新型滤波器能根据信号的复杂程度自动调节其参数 ,对宽带噪声中非平稳随机信号有较好的滤波效果     

Investment in production resource flexibility: An empirical investigation of methods for planning under uncertainty

We examine several methods for evaluating resource acquisition decisions under uncertainty. Traditional methods may underestimate equipment benefit when part of this benefit comes from decision flexibility. We develop a new, practical method for resource planning under uncertainty, and show that this approach is more accurate than several commonly used methods. We successfully applied our approach to an investment problem faced by a major firm in the aviation information industry. Our recommendations were accepted and resulted in estimated annual savings in excess of $1 million (US). © 2003 Wiley Periodicals, Inc. Naval Research Logistics, 2003