对地攻击机靶场作战效能的基本问题

讨论了对地攻击靶场作战效能分析过程中所涉及到的主要问题及靶场作战效能指标的计算原理,简要介绍了一个实用的对地攻击机靶场作战效能分析软件的主要功能.     

美国SpaceX公司技术创新的启示

文章研究信息化时代陆军作战领域、作战形式、力量融合方式和打击手段的不断更新,对陆军主要作战行动样式发生的深刻变化进行了分析。     

Combined variance reduction techniques in fully sequential selection procedures

In the past several decades, many ranking‐and‐selection (R&S) procedures have been developed to select the best simulated system with the largest (or smallest) mean performance measure from a finite number of alternatives. A major issue to address in these R&S problems is to balance the trade‐off between the effectiveness (ie, making a correct selection with a high probability) and the efficiency (ie, using a small total number of observations). In this paper, we take a frequentist's point of view by setting a predetermined probability of correct selection while trying to reduce the total sample size, that is, to improve the efficiency but also maintain the effectiveness. In particular, in order to achieve this goal, we investigate combining various variance reduction techniques into the fully sequential framework, resulting in different R&S procedures with either finite‐time or asymptotic statistical validity. Extensive numerical experiments show great improvement in the efficiency of our proposed procedures as compared with several existing procedures.     

Comparison of rank aggregation methods based on inherent ability

Ranking is a common task for selecting and evaluating alternatives. In the past few decades, combining rankings results from various sources into a consensus ranking has become an increasingly active research topic. In this study, we focus on the evaluation of rank aggregation methods. We first develop an experimental data generation method, which can provide ground truth ranking for alternatives based on their “inherent ability.” This experimental data generation method can generate the required individual synthetic rankings with adjustable accuracy and length. We propose characterizing the effectiveness of rank aggregation methods by calculating the Kendall tau distance between the aggregated ranking and the ground truth ranking. We then compare four classical rank aggregation methods and present some useful findings on the relative performances of the four methods. The results reveal that both the accuracy and length of individual rankings have a remarkable effect on the comparison results between rank aggregation methods. Our methods and results may be helpful to both researchers and decision‐makers.     

无人机电磁弹射器效能分析

无人机电磁弹射器是一个由多子系统构成的装备,且各部分之间联系紧密,并不同程度的影响着整体效能。为了确定各组成部分与电磁弹射器效能的影响关系,对其进行系统评价,将系统的整体效能分解为几种典型的效能指标,并采用关联矩阵法(RMA)对由弹射器子系统和效能指标构成的评价体系进行分析。明确了电磁弹射器各部分对系统效能的影响程度,并给出了提高电磁弹射器效能指标的几点建议。     

MgSO4弛豫吸收对水下强声波脉冲传播的影响分析

对水下等离子体放电强声波脉冲实验测量波形进行FFT变换发现,其能量主要集中在100kHz以下的频段内,在这个频段内,海水中存在的一种盐类——MgSO4(硫酸镁)化学弛豫会造成声波的逾量吸收.本文从包含海水中MgSO4弛豫吸收的修正物质状态方程出发,推导了强声波脉冲传播的新的波动方程,并结合具体的数值算法,对强声波脉冲的传播进行了数值模拟,分析了MgSO4弛豫吸收对脉冲波形的传播及频谱的影响.研究表明,MgSO4弛豫吸收对陡峭的冲击脉冲波形具有平滑和展宽作用,使得脉冲的能量更靠近低频.这种效应与球面波阵面的几何扩散相结合,造成了强声波脉冲能量的逾量损失.     

倾斜转弯高超声速飞行器滚动通道的自适应全局积分滑模控制

针对倾斜转弯高超声速飞行器滚动通道控制中初始误差大、系统参数不确定和干扰严重的问题,设计了一种自适应全局积分滑模控制方法.该方法在滑模控制参数中引入了自适应调节律来逼近系统参数摄动和干扰的上界,保证了整个控制过程中的滑模可达性,在此基础上,设计了一种基于全局积分滑模面的自适应滑模控制器,消除了稳态误差,同时大大削弱了系统参数不确定和干扰对系统的动态影响,并使系统在初始阶段就处于滑模态,解决了大的初始误差引起的超调问题.理论分析和仿真结果验证了本文所提方法的有效性.     

修正的逻辑航迹起始算法

根据目标的运动特性提出了一种基于修正逻辑的航迹起始方法,其主要思想是在航迹起始阶段,对落入相关域中的量测加一个限制条件,以剔除在一定程度上与航迹成V字形的测量点迹。仿真结果表明,这种方法可以有效地在杂波环境中快速获得起始航迹,具有较好的实用价值。     

CAI课件开发中的数据库应用

本文在分析CAI课件开发中测试部分设计难点的基础上,结合实例阐述了使用多媒体课件制作工具Authorware开发CAI课件时,如何通过ODBC数据库接口和SQL语言,以外部数据库作为数据源,实现不同章节抽取测试题的方法。     

FPGA在程控数字交换机中的应用研究

针对现有程控数字交换机大多采用传统搭积木式(即用器件搭成电路板)的设计方法,提出用现场可编程门阵列(FPGA)技术设计的新思路,并通过VHDL语言设计给出了仿真结果,结果表明,用FPGA设计的数字程控交换模块具有硬件结构简单、性能良好、功能易于升级等优点.