分布式作战仿真接口概念设计

接口设计是实现分布式作战仿真互操作的关键。本文在对高层体系结构研究的基础上 ,提出了一种基于状态空间影子模型的接口概念设计方案 ,分析和论述了相关系统结构、接口数据的表达、接口的构成及其工作原理。     

自动目标识别(ATR)技术发展述评

能够自动进行目标识别 ( ATR)是现代武器装备力争具备的先进性能之一。从历史回顾、当前状态及未来发展等几个方面对自动目标识别的研究历程、技术现状和发展前景进行了较为详细的论述 ,并指出了当前发展中遇到的主要技术难题及可能的解决办法     

网格技术与全球信息网格

网格技术被认为是互联网技术发展的下一次浪潮,目前对网格的研究已经成为信息领域的热点.本文阐述了网格的定义、由来、特性、标准化、协议等,介绍了网格技术在军事上的应用、美军全球信息网格(GIG)的计划,以及全球信息网格与网络中心战的关系.     

Exact analysis of (R,s, S) inventory control systems with lost sales and zero lead time

We study an (R, s, S) inventory control policy with stochastic demand, lost sales, zero lead‐time and a target service level to be satisfied. The system is modeled as a discrete time Markov chain for which we present a novel approach to derive exact closed‐form solutions for the limiting distribution of the on‐hand inventory level at the end of a review period, given the reorder level (s) and order‐up‐to level (S). We then establish a relationship between the limiting distributions for adjacent values of the reorder point that is used in an efficient recursive algorithm to determine the optimal parameter values of the (R, s, S) replenishment policy. The algorithm is easy to implement and entails less effort than solving the steady‐state equations for the corresponding Markov model. Point‐of‐use hospital inventory systems share the essential characteristics of the inventory system we model, and a case study using real data from such a system shows that with our approach, optimal policies with significant savings in inventory management effort are easily obtained for a large family of items.     

Surface modification of ammonium nitrate by coating with surfactant materials to reduce hygroscopicity

Ammonium nitrate (AN) is promising oxidizer in green propellants. In this work, the physical coating method was improved to modify the surface of ammonium nitrate particles with different surfactant materials to reduce hygroscopicity. Cetylalcohol, stearic acid, stearyl alcohol, palmic acid, lauric acid, stearsmide, tetradecylamine, dodecylamine, and tetradecanol were used as coating surfactant agents. The hygroscopicity was tested for ammonium nitrate with and without coating. Fourier transform infrared (FTIR) and scanning electron microscopy (SEM) were used to characterize the surface of coated and uncoated ammonium nitrate. The mass ratio of coating layer and decline of absorption rate of ammonium nitrate coated by cetylalcohol were 1.00%, and 28.40%, respectively. The results indicate that coating with cetylalcohol surfactant have advantages over the other surfactants in term of low mass ratio of coating layer, and high decline of moisture absorption rate. Thus, cetylalcohol would be a promising coating surfactant material for ammonium nitrate. The idea and approach presented in this study have potential to made hydrophobic layer on the surface of particles to reduce hygroscopicity of AN, and also help the researcher to improving anti-hygroscopicity of ammonium salts.     

Firm embedding behavior of annular grooved projectiles impacting ductile metal targets

Annular grooved projectiles (AGPs) have drawn ongoing concerns as an advanced penetrator for their excellent anti-rebound capability in impacting metal plates. They could become embedded solidly in the target surface during low-velocity impact. In this investigation, the firm embedding behavior of AGP was observed by impact experiments. Corresponding numerical simulations provided a better understanding of this process. Experimental and numerical results indicated that the firm embedding behavior of AGP was mainly due to the filling-material in the groove rather than the friction between the projectile and target, unlike traditional shape such as conical projectile. According to observation, firm embedding process can generally be subdivided into four stages: initial-cratering stage, groove-filling stage, filling-material failure stage and rebound vibration stage. Moreover, the damage mechanics of target material around crater was obtained through microscopic tests. A comparison of the cross-sectional figures between the experiment and simulation proved that the analysis and the proposed method were reasonable and feasible, which further demonstrated that the firm embedding behavior has application potential in new concept warheads.     

面向装备体系作战效能评估的SEM建模与评估方法

针对装备体系作战效能评估分析需求,构建了基于SCA（ Sensor?Controller?Actuator）的装备体系作战能力评估指标体系,研究了基于SEM（ Structural Equation Modeling）的装备体系作战效能评估方法,并以某防空反导装备体系作战效能评估为例,验证了方法的合理性和有效性。该研究可为装备体系发展论证及作战效能评估提供参考。     

一种改进的无参考图像质量评估算法

无参考图像质量评估方法一直是图像质量研究所关注的重点。本文针对无参考图像质量评估问题,在当前被广泛接受的 DIIVINE 图像质量评估方法基础上进行了深入的研究,研究发现经典的 DIIVINE 方法中使用了过多的统计特征量,由于统计量无差别的使用影响了方法的预测性能。基于此,利用主成分分析（PCA）算法对该特征向量进行降维,得到“精简的特征向量”,用此向量可以达到更好的分类性能和评估性能。试验证明,在图像数据库上,该算法表现出较好的预测性能,其性能优于其他主流的无参考图像评估算法。     

金属泡沫断裂韧性的试验研究

金属泡沫在其实际应用中,断裂性能和断裂韧性对于承载的多孔金属泡沫有着重要的意义。基于美国试验材料学会相关标准,采用三点弯曲试样测定了铝泡沫的I型断裂韧性。研究表明,金属泡沫的断裂为脆性断裂,在裂纹尖端附近,孔壁最薄弱的区域最容易发生变形;随着进一步加载,一些孔壁发生断裂,微裂纹在断裂尖端附近出现。随着载荷的增加,主裂纹在缺口根部形成或由微裂纹合并而成,并开始在多孔结构内传播。裂纹沿着结构最薄弱处传播,并产生次生裂纹和裂纹桥。裂纹总的扩展方式还是I型断裂。根据试验P-V曲线特点,取最大载荷点对应的力与位移求解出铝泡沫的裂纹尖端临界张开位移的平均值为0.051 mm。     

认知MIMO雷达波形设计研究

认知多输入多输出(multiple-input multiple-output,MIMO)雷达将认知技术与MIMO技术相结合,具备动态环境信息感知和自适应调节能力,受到雷达界的广泛关注。相比于传统雷达,认知MIMO雷达性能更优、适应性更强,是雷达迈向智能化发展的趋势,而发射波形的优化设计是实现雷达认知的关键,因而成为近年来学者研究的重点。首先介绍了认知MIMO雷达基本概念,分析了波形设计现状,然后在波形设计步骤的基础上,重点从优化准则和优化方法两方面总结了现有研究成果及特点,最后讨论了未来研究方向和需要解决的问题。