Factors that affect the optimal amount of central control in complex systems

Whereas much of the previous research in complex systems has focused on emergent properties resulting from self‐organization of the individual agents that make up the system, this article studies one vital role of central organization. In particular, four factors are conjectured to be key in determining the optimal amount of central control. To validate this hypothesis, these factors are represented as controllable parameters in a mathematical model. For different combinations of parameter values, the optimal amount of central control is found, either analytically or by computer simulation. The model is shown to provide results that match well with the level of control found across a broad spectrum of specific complex systems. This model also provides general guidelines as to how combinations of these factors affect the desirable level of control and specific guidelines for selecting and evaluating leaders. These results indicate that all of these factors, though not exhaustive, should be considered carefully when attempting to determine the amount of control that is best for a system. © 2008 Wiley Periodicals, Inc. Naval Research Logistics, 2008     

固体发动机药柱正交各向异性材料参数灵敏度分析

<正>交各向异性材料已在大型固体发动机上得到广泛应用。为了较大地降低发动机药柱的VonMises应变水平,极大地提高发动机的结构完整性能,以星形药柱为例,对固体发动机药柱推进剂和绝热层的弹性模量和泊松比等正交各向异性材料参数进行了灵敏度分析,得到了固体发动机药柱正交各向异性材料参数的灵敏度系数。分析方法与结论对固体发动机的优化设计具有指导作用。     

Improving series and parallel systems through mixtures of duplicated dependent components

We discuss suitable conditions such that the lifetime of a series or of a parallel system formed by two components having nonindependent lifetimes may be stochastically improved by replacing the lifetimes of each of the components by an independent mixture of the individual components' lifetimes. We also characterize the classes of bivariate distributions where this phenomenon arises through a new weak dependence notion. © 2011 Wiley Periodicals, Inc. Naval Research Logistics, 2011     

改进合同网协议的Agent动态任务分配

针对导弹作战任务规划中的动态任务分配问题,研究了MAS框架下任务分配的形式化描述和数学模型,对动态任务分配的特点进行了分析,运用合同网理论,提出了基于改进合同网协议的Agent动态任务分配算法,实现了对不确定开放环境中动态变化的任务分配方法。算例表明算法是有效的。     

系统论在医院护士在职教育中的应用

在系统论的指导下,分析医院护士在职教育这个子系统的构建、运行方法、效果评价和存在的问题。     

机动管线流量在线实时监测技术研究

输送流量在线实时监测是准确掌握机动管线运行工况、优化运行方案、分析判断泄漏的关键之一。分析了容积式、速度式和差压式等常用流量监测技术的技术特征与使用条件,根据机动管线的作业特点和要求,优选出涡街流量监测技术作为该管线系统的流量在线实时监测技术;分析了机动管线输送过程中管道振动对涡街流量计计量精度的影响,提出了几种不同的抗振防干扰技术,并应用于机动管线涡街流量监测装置的研制。样机试验表明,采用抗振技术的涡街流量监测装置检测精度能满足机动管线流量在线实时监测需求。     

基于超网络的作战体系建模方法

基于信息系统体系作战问题研究的基础是作战体系构建。在对作战体系进行网络化结构分析的基础上,重点考虑体系中各类实体及属性的复杂性,根据其网络拓扑特性,以超网络、超图理论为指导,建立了基于结构层和属性层相统一的超网络模型,并结合体系作战过程中的对抗规律,提出超网络模型相应的动态演化方式,最后通过案例建模验证了超网络作战体系构建模型的适应性及优势。     

多机器人编队控制研究

多机器人编队控制是多机器人协调控制中一个最具有挑战性的研究问题。多机器人编队是指：一组相互协作的机器人组建和保持特定的队形形状。本文首先简要概述了多机器人编队问题的研究现状。从面向问题的角度出发,本文将编队问题分解成编队角色分配、队形生成、队形变换与选择、编队跟踪4个子问题,并针对每个子问题,总结了现有的研究方法。最后,本文特别强调编队控制中的网络问题并指明未来的研究方向。     

基于解析结构模型的网络空间信息防御能力分析

针对网络空间信息防御需求及特点,利用解析结构模型方法,分析网络空间信息防御能力的影响要素及其关系,建立网络空间信息防御能力影响要素的层次结构模型,并找出核心要素和关键环节,为网络空间信息防御能力建设提供决策支持。     

Resistance of grid steel-tube-confined concrete targets against projectile impact: Experimental investigation and analytical engineering model

Steel-tube-confined concrete (STCC) targets are provided with excellent anti-penetration performance over semi-infinite concrete (SIC) targets since the steel tube imposes passive restraint on the in-filled concrete during the penetration process. Grid STCC system with square steel tubes is a potential solution to protective structures. In this paper, experiments of 9-cell grid STCC targets penetrated by 12.7 mm Armor Piercing Projectile (APP) were performed. The influence of side length and thickness of steel tube, steel ratio and impact velocity on anti-penetration performance were taken into account. Additionally, single-cell square STCC targets were also designed and tested for comparison with the 9-cell grid STCC targets. Damage modes and parameters of the tested targets were measured and discussed. Moreover, the stiffness of radial confinement of grid STCC targets is achieved according to the elastic solution of infinite cylindrical shell in Winkler medium. Furthermore, the penetration resistance and depth of penetration (DOP) for grid STCC targets are obtained on the basis of the dynamic finite spherical cavity-expansion (FSCE) models including radial confinement effect. It is shown that the 9-cell grid STCC targets with optimal dimension match of thickness and side length of steel tube can reduce the DOP by about 17 % and 23 % in comparison with the SIC targets and single-cell square STCC targets, respectively, due to both the confinement of square steel tube to concrete in the impacted cell and the additional confinement of the surrounding cells to the impacted cell; the penetration resistance and DOP of the grid and cellular STCC targets with similar steel ratio is close, and thus the grid STCC targets with simpler manufacturing process and excellent in-plane expandability are preferred in engineering practice; moreover, the predicted results of DOP model based on the FSCE models agree well with the tested results with the maximum disparity less than 12 % and the proposed model is more applicable to the grid and cellular STCC targets with high radial confinement.