电缆隧道中细水雾灭火系统的试验评价与优化设计

细水雾作为哈龙灭火剂的重要替代技术,在电缆隧道中具有广阔的应用前景。然而由于其灭火机理的复杂性,在细水雾灭火系统的设计中不能完全依赖于一般性原则或统一的标准。以浦东国际机场二期工程电缆隧道高压细水雾保护系统的实际应用为例,通过建立全尺度的模拟试验,对细水雾灭火系统设计参数的有效性和科学性进行评估,优化系统设计,以满足电缆隧道特殊的消防安全需求。研究结果表明该方法为细水雾系统设计达到有效性、安全性、经济性的统一提供了合理解决途径。     

超音速等离子喷涂连续梯度热障涂层工艺优化研究

采用"双通道、双温区"超音速等离子喷涂工艺制备了Ce-YSZ/NiCoCrAlY连续梯度热障涂层(CG-TBCs)。借助热喷涂粒子状态在线监测系统Spraywatch-2i,分别研究了电弧功率、喷涂距离对Ce-YSZ/NiCoCrAlY粒子速度和温度的影响。实验结果表明,当电弧功率为70 kW和68 kW时,Ce-YSZ与NiCoCrAlY粒子速度达到最高,分别为620 m/s和430 m/s。Ce-YSZ和NiCoCrAlY粉末粒子的平均温度均随电弧功率的增加而上升,但当功率分别达到60 kW和65 kW时,粒子温度的上升趋势不再明显。电弧功率选择在68 kW,喷涂距离定为90 mm左右时,制备的CG-TBCs在经历100次热循环后,其表面和内部均未出现明显的裂纹,具有优异的热震性能。     

Optimizing the US Navy's combat logistics force

We study how changes to the composition and employment of the US Navy combat logistic force (CLF) influence our ability to supply our navy worldwide. The CLF consists of about 30 special transport ships that carry ship and aircraft fuel, ordnance, dry stores, and food, and deliver these to client combatant ships underway, making it possible for our naval forces to operate at sea for extended periods. We have modeled CLF operations to evaluate a number of transforming initiatives that simplify its operation while supporting an even larger number of client ships for a greater variety of missions. Our input is an employment schedule for navy battle groups of ships operating worldwide, extending over a planning horizon of 90–180 days. We show how we use optimization to advise how to sustain these ships. We have used this model to evaluate new CLF ship designs, advise what number of ships in a new ship class would be needed, test concepts for forward at‐sea logistics bases in lieu of conventional ports, demonstrate the effects of changes to operating policy, and generally try to show whether and how the CLF can support planned naval operations. Published 2008 Wiley Periodicals, Inc. Naval Research Logistics 2008     

先期毁伤原则下武器单元的射击时机分配

以先期毁伤为原则,首次对武器单元的射击时机分配问题进行数学建模。提出一种使毁伤概率密度在时间上靠前分布的武器单元射击时机分配模型,在保证指定瞬时之前以期望概率毁伤目标的前提下,合理分配各武器单元的射击时机,实现对目标的尽早毁伤。根据射击时机分配模型中约束函数的单调性特点,提出一种改进的连续域蚁群算法,使算法自变量满足约束条件的"优良区域"开始搜索,采用搜索窗口平移的方法逐步寻找最好解,提高了算法的搜索速度。实例分析验证了模型和算法的有效性。     

流动危险源泄漏事故应急疏散决策优化

在流动危险源泄漏事故中,如何根据流动危险源的危险特性,快速制定最优疏散决策,使应急疏散的成本最低是现场指挥人员急需解决的重要问题。在分析讨论疏散范围、疏散人员、疏散方式、疏散路径、避难场所等影响应急疏散决策因素的基础上,采用线性规划方法,建立了应急疏散的优化模型。以运输液氯槽车泄漏事故为例,研究危险区域的人员疏散,并利用Lingo软件对优化模型进行了求解,得到了应急疏散的最佳方案。研究结果对消防部队有效地指导疏散救人行动具有参考价值。     

化学反应驱动热机的功率优化

本文基于一级和二级化学反应动力学理论,讨论化学反应驱动有限热容热源内可逆卡诺热机系统的功率优化问题,得到了一些新的结果。     

极大代数及其在离散事件动态系统中的应用

在人类社会活动中,有许多活动属于离散事件或离散事件动态系统。在极大代数意义下,这类系统可用线性系统的理论和方法建立数学模型、求解状态方程,讨论可控性、可观性,以及实现系统运行的优化设计。     

轴流泵出口环量变化规律与几何参数一体化最优设计方法

最近十几年来,叶轮机械最优设计取得了很大进展。作为其最优设计系统的一个典型环节,叶片泵的设计优化得到了重视。近年来,我国开始探索采用变轴面速度、变环量流型进行轴流泵水力设计,并讨论环量分布规律的优化问题。文献针对不同的目标函数,分别求解叶轮直径及出口环量分布规律最佳值,这等于把一个完整的问题分解了,并不一定能保证     

An eikonal equation based path planning method using polygon decomposition and curve evolution

Path planning is a key technique of autonomous navigation for robots, and the velocity field is an important part. Constructing velocity field in a complex workspace is still challenging. In this paper, an inner normal guided segmentation algorithm in a complex polygon is proposed to decompose the complex workspace in this paper. The artificial potential field model based on probability theory is then used to calculate the potential field of the decomposed workspace, and the velocity field is obtained by utilizing the potential field of this workspace. Path optimization is implemented by curve evolution, during which the internal force generated in the smoothing process of the initial path by a mean filter and the external force is obtained from the gradient of the workspace potential field. The parameter selection principle is deduced by analyzing the influence of several parameters on the path length and smoothness. Simulation results show that the designed polygon decomposition algorithm can effectively segment complex workspace and that the path optimization algorithm can shorten and smoothen paths.     

无运力限制条件下的一种器材紧急调运优化模型

根据器材调运的特点建立了一个货量充足且无运力限制条件的多目标优化模型,给出了一种方便有效的算法,并利用仿真算例对模型和算法进行了验算,得到了最优的器材调运方案.