基于交叉定位的满足定位精度区域仿真研究

通过雷达组网对空中目标进行交叉定位是现代防空雷达的一个重要发展方向,分析了被动交叉定位抗击干扰目标的定位精度,对作战地域进行网格剖分,仿真得出满足一定精度要求的区域,并且在电子地图上形象地显示出来,便于指挥员进行快速决策。通过实际应用验证了该仿真算法的正确性和实用性。     

舰载雷达有源标校方法研究

为了对舰载雷达进行准确、快速标校，讨论应用有源标进行舰载雷达标校的方法以及应注意的几个问题。介绍了该方法的原理，给出了相关数学模型及公式，并进行了数据分析。应用该方法能够同时对舰艇上安装于不同位置的多部雷达进行标校。该方法已在某型舰艇两部雷达标校中得到成功应用。     

舰载强激光武器系统精度指标分析

着重研究了舰载强激光武器的两个方面:一是在现代海战条件下的作战应用,以强激光武器的性能优势,拦截现有防空武器难以拦截的突防精确制导武器;二是研究了强激光武器光束控制系统的精度指标分析方法,并将该方法应用于舰载强激光武器光束控制系统的参数设计.     

基于CCD技术的火控自动复瞄精度测试方法

分析了火控系统自动复瞄精度现有测试方法，提出了一种采用高分辨率的CCD光电系统测试自动复瞄精度的新方法，该方法具有很高的实用价值。     

Traffic channeling under uncertain conversion rates on e-commerce platforms

Traffic is the lifeblood of every e-commerce platform. The question of how to channel traffic to merchants operating on a platform lies at the heart of platform management. We consider a platform on which two independent merchants sell their products. Merchants compete on inventory in the sense that some of the unmet demand at one merchant will spill over to the other. The platform channels traffic based on products' conversion rates to maximize the total sale on the platform. We show that traffic channeling plays three roles. First, it allows more efficient allocation of traffic; that is, the merchant with a high conversion rate is given a higher priority in receiving traffic. Second, it allows the platform to control demand spillover between the merchants to maximize total sales. The platform either facilitates or prevents demand spillover, depending on product substitutability. Third, traffic channeling intensifies competition between the merchants and hence increases the total inventory. More efficient allocation of traffic and the increase in inventory increase sales inequality between the merchants. In contrast, demand spillover decreases sales inequality. While the platform always benefits from traffic channeling, the merchants do not benefit when their products are moderately substitutable. Interestingly, when the two products are owned and sold by the same merchant, the opposite happens–traffic channeling always benefits the merchant but may hurt the platform. Our study provides a basis for informed discussions on how platforms should channel traffic in response to conversion rates, and how traffic channeling affects the welfare of merchants and platforms.     

防空火控网数据传输精度分析与测量

巡航导弹在战争中的大量使用已经改变了现代战争的作战模式,如何有效发现和捕获低空飞行目标成了传统防空火控系统面临的一大难题,防空火控系统组网作战是未来防空武器装备发展的必然趋势.分析了防空火控网中影响数据传输精度的各种原因,针对防空火控网中空情数据传输精度的测量,给出了同步测量和异步测量两种方法.     

基于电磁能的生命探测技术研究(英文)

根据人体在电磁场中的感应特性以及电磁波的能量转换规律,提出了基于电磁能的生命探测器设计方案.首先探讨该探测器的理论原理,它是利用电磁波发送和接收的能量转换规律及人体在磁场中的感应特性,研究了人体对电磁场中能量转化的影响;接着利用该原理研制开发了生命探测器,并进行实验验证.实验结果表明,当人体进入该探测器产生的静电场时,探测器能够正确检测到人的存在.     

基于Matlab的影响子母弹抛撒精度的因素研究

本文通过对子弹运动方程及子母弹毁伤模型的研究,分析了影响子母弹抛撒精度的因素.基于实验数据,利用Matlab对不同影响因素下的抛撒精度进行了仿真与分析.结果表明:抛撒高度和抛撒药量是对抛撒精度影响较大的因素.     

PWM调制方式对六相无刷直流电动机转矩脉动的影响分析

建立了六相无刷直流电动机(BLDC)的相绕组数学模型,在此基础上分析了该电机在 PWM 调制方式下的非换相期间关断相电流的产生过程.分析结果表明,在采用PWM_ON_PWM调制方式时,可以消除多相 BLDC 的非换相期间关断相电流,因此可以降低转矩脉动.此外,还分析了该电机在换相期间的转矩脉动情况,得到了由换相引起的转矩脉动解析表达式,并给出了消除转矩脉动应该满足的 PWM 占空比控制条件.     

Investigation on the spatial distribution characteristics of behind-armor debris formed by the perforation of EFP through steel target

The behind-armor debris (BAD) formed by the perforation of an EFP is the main damage factor for the secondary destruction to the behind-armor components. Aiming at investigating the BAD caused by EFP, flash X-ray radiography combined with an experimental witness plate test method was used, and the FEM-SPH adaptive conversion algorithm in LS-DYNA software was employed to model the perforation process. The simulation results of the debris cloud shape and number of debris were in good agreement with the flash X-ray radiographs and perforated holes on the witness plate, respectively. Three-dimensional numerical simulations of EFP's penetration under various impact conditions were conducted. The results show that, an ellipsoidal debris cloud, with the major-to-minor axis radio (a/b) smaller than that caused by shaped charge jets, was formed behind the target. With the increase of target thickness (h) and decrease of impact velocity (v₀) and obliquity (θ), the value of a/b decreases. The number of debris ejected from target is significantly higher than that from EFP. Based on the statistical analysis of the spatial distribution of the BAD, An engineering calculation model was established considering the influence of h, v₀ and θ. The model can with reasonable accuracy predict the quantity and velocity distribution characteristics of BAD formed by EFP.