机场未爆弹识别技术应用研究

由于机场未爆弹识别具有模糊性和风险性的特点,尝试把最近发展起来的模糊支持向量机引入到机场耒爆弹探测中.首先对数据进行预处理,得到各点的风险隶属度,并将其引入决策函数的生成过程.机场未爆弹探测试验结果表明最后得到的决策函数对重要数据的分类精度有明显改善.     

基于关键点的未爆弹图像目标检测算法

针对排爆机器人智能识别未爆弹的问题，提出一种基于关键点的未爆弹图像目标检测算法。首先以ResNet-50为主干网络，对未爆弹图像进行初步特征提取，然后引入分离注意力模块的特征增强网络，增强了对未爆弹目标图像背景复杂和存在遮挡现象的适应能力，最后输入头部预测模块得到未爆弹类别和位置信息。实验结果表明，本算法能够取得较高的检测精度和实时性，为各类未爆弹的鉴定和排爆机器人向自主排爆提供了便利。     

基于SPH算法的钢球高速撞击肥皂数值仿真

运用光滑粒子流体动力学分析方法,对钢球高速侵彻肥皂靶标进行了数值仿真分析。建立了钢球与肥皂高速撞击数值计算模型,运用侵蚀接触算法,求解了高速钢球侵彻肥皂的动力响应时间历程,获取了钢球侵彻肥皂靶标的侵彻深度与投射物速度关系图和瞬态Von—Mises等效应力云图,分析了高速碰撞过程及碰撞过程中空腔的形成和变化情况,并与实验结果及Lagrange数值仿真结果对照,计算结果具有良好精度,表明运用SPH方法能够较好地描述高速撞击现象。文中的研究表明,SPH技术是开展创伤弹道研究的有效手段。     

等面密度钢/铝组合靶的抗侵彻性能研究

金属靶板的抗侵彻性能一直以来都是被重点关注的研究领域。为明确结构参数对钢/铝组合结构抗步枪弹垂直侵彻性能的影响,建立了步枪弹侵彻钢板和铝板的数值计算模型,并通过弹道冲击实验进行了验证;进而基于数值计算模型分析了相同厚度下钢-铝、铝-钢的组合形式、靶板间距对组合靶板抗侵彻性能的影响。仿真结果表明：相同厚度下,钢板在前的组合形式优于铝板在前的靶板,但不同组合形式的层板间距对其抗侵彻性能影响较小;另外,比较了不同初速度下钢-铝厚度比的变化对组合靶板的抗侵彻性能影响,均呈现出随厚度比增加,抗侵彻性能先降低后增加的趋势,最终趋于一个稳定值。变化过程中存在一个抗侵彻性能最差的低点,在结构设计中应尽可能避开。最后,依据R-I公式拟合了仿真数据,得到了步枪弹侵彻钢-铝组合结构的弹道极限公式。研究结果可为组合靶板的抗侵彻性能设计和人员、物资防护提供参考。     

跨介质飞行器弹道仿真分析

研究气/水跨介质飞行器的动态特性,跨介质飞行器是一种新型概念飞行器,为了了解跨介质飞行器的运动特点,提出建立了跨介质飞行器的运动数学模型,对弹道进行仿真研究.通过对跨介质飞行器的空间运动进行受力分析,进行跨介质飞行器三种典型弹道的仿真分析.仿真结果基本完成了跨介质飞行器起飞巡航弹道,贴水滑行弹道以及触水滑跳弹道三种典型弹道的仿真,而且由于跨介质飞行器的浸水深度较小,极大地降低了水阻力的影响,可以达到较高的航行速度,为气/水跨介质飞行研究提供了依据.     

一种新型未爆弹探测传感器的仿真研究

位于地表和近地表的未爆弹通常种类多,分布情况复杂,危险性高,这严重阻碍了土地的开发和利用.在实际探测中未爆弹所产生的二次场十分微弱,探测困难,有效信息较少.针对此情况,设计了一种基于频域电磁法的新型未爆弹探测传感器,其激励线圈与接收线圈剩余耦合低,具有较好的灵敏度和稳定性.对此电磁传感器进行了有限元分析,结果表明,该传...     

超空泡射弹对硬铝薄板的斜侵彻特性研究磁

运用ANSYS／LS‐DYNA动力学仿真软件对超空泡射弹斜侵彻硬铝薄靶进行数值模拟,获得了不同弹着角和攻角下破口形状尺寸、射弹运动轨迹、弹道极限速度等参数的变化规律,从定性的角度着重探讨了弹着角和攻角的存在对侵彻效能的影响。仿真分析表明,侵彻过程中弹着角和攻角的存在会引起弹道的偏转和射弹应力的升高,从而降低射弹的侵彻能力。然而弹着角和攻角均会导致靶板损坏尺寸的增大,更有利于靶板的毁伤。     

聚能装药侵彻混凝土数值模拟

采用自主开发的EXPLOSION-2D软件对不同锥角药型罩结构的聚能装药成型进行数值模拟,结果表明:随着药型罩锥角的增加,侵彻体的头部速度和长度均不断减小,导致其侵彻能力下降,但侵彻体直径不断增加使得其侵彻孔径增加.因此,设计一种在炸药内开槽的装药结构,并对炸药内部开槽位置以及槽的高度和宽度对侵彻体侵彻能力的影响进行数值模拟,获得其对侵彻体侵彻性能的影响规律.结果表明:开槽位置以及槽的高度和槽的宽度均存在一个最佳值,使得侵彻体侵彻混凝土性能达到最佳,由此说明合理的设计开槽结构能够有效提升侵彻体侵彻混凝土的有效深度.     

基于高速以太网的数字化靶道设计

随着对高新武器研究的深入,弹道试验对全弹道测试的综合集成要求将越来越高,而国内大多数弹道靶道仍停留在常规武器的研究水平上,试验测试能力有待提高。针对国内大多数靶道的现状,提出了基于网络化测控技术的数字化靶道设计方法,旨在实现内弹道、中间弹道、外弹道和终点弹道不同测试任务的有机结合,在得到试验结果综合性评价的同时提高试验效率,以适应高新武器研究的需要。     

强干扰条件下机场道面细小裂缝自动识别算法

针对机场道面裂缝极其细小,而基于深度相机的裂缝检测技术面临道面表观结构复杂和平台剧烈震动的双重强干扰的难题,提出了结合L2正则化与动态阈值贪心策略的道面主轮廓建模算法,并基于此实现了机场道面毫米级细小裂缝的精确检测。首先,设计了基于L2正则化约束的道面主轮廓模型估计方法,解决了因表观结构复杂而导致的道面主轮廓过拟合问题;其次,提出基于动态阈值的改进贪心算法,通过迭代去除异常点的方式抑制检测平台震动带来的噪声干扰;最后,基于构建的道面主轮廓模型,提取并融合多方向的机场道面主轮廓,并利用裂缝的深度与形态信息实现裂缝提取。通过在真实机场道面数据集上的测试结果表明,该算法能够精确地完成道面主轮廓重建和细小裂缝识别,且识别性能优于多种现有经典的裂缝检测算法。     

An intelligent method to block e-mail bombs

It is hard to block e-mail bombs because they are usually sent by normal SMTP (Simple Mail Transfer Protocol) applications with fake mail sender addresses and IP addresses. Fortunately, original network packets contain real IP address information anyway. Collecting and analyzing these packet contents can help an administrator to realize where the e-mail bombs are coming from and block them. This article presents a simple method that uses a bandwidth manager device to collect and analyze packets to get e-mail bombs information as well as to block e-mail bomb source IP addresses in routers. In practical application experiences at the computer center in a university, this method blocked e-mail bombs simply and effectively. Furthermore, a fuzzy inference system was also designed to help identify e-mail bombs. Its fuzzy membership functions could be adapted using the fuzzy neural network learning method. In brief, the proposed method affords an automatic and adaptable alarm to find e-mail bombs.     

烟花爆炸优化算法

本文受烟花爆炸现象启发,提出一种新的并行弥漫式搜索的优化算法(FEO),为解决优化问题提供了一种新的基础算法。该算法在搜索空间中生成一定数目的烟花弹,对每个烟花弹执行爆炸操作,使得爆炸产生的大量火星形成在原烟花弹(炸点)的一定邻域范围内,并采用局部保优的策略逐代控制进行爆炸的烟花弹数。同时,通过调整烟花弹爆炸的最大半径,可以均衡算法的全局探索和局部搜索能力。为了研究FEO算法的性能,文中对一些标准的测试函数进行了验证。大量的实验结果表明,FEO算法具有快速的收敛过程和高精度的寻优能力,并且稳定性好,过程简单,易于实现。     

Google Bombing from a Time Perspective

Google bombing is a collective attempt to change the placement of some documents in Google's result list for a given query. This can be achieved by extensive linking to the page to be promoted, since Google's ranking algorithm takes into account the quantity and quality of links pointing to a page. This article investigates whether the effects of Google bombing are long term or whether the interest in promoting a page diminishes over time. Nine Google bombs that were once successful and were 10-40 months old as of August 2005 were examined, and the content of a random 20% of the pages linking to the targeted pages was analyzed. The results of the content analysis show that the behavior of the Google bombs over time seems to be dependent on the type of Google bomb (humor, ego, or ideological) and on the community promoting the bombed page. Six of the targeted pages still occupied top positions, while three lost their effect over time.     

某导弹测试训练及评价系统研制

为了解决武器装备测试训练过程中装备损害、性能下降、无法提供所有故障现象等问题,本课题设计了某型号导弹测试训练系统,包括训练弹和测试训练及评价软件。训练弹具有和真实弹完全一致的外形、电气接口,能够设定故障模式,进行测试训练,故障诊断训练。测试训练及评价软件使用Lab Windows/CVI开发,能够自动识别真实弹和训练弹,并对训练过程进行评价。目前,该系统已经交付使用。     

Collision detection between point clouds using an efficient k-d tree implementation

Context: An important task in civil engineering is the detection of collisions of a 3D model with an environment representation. Existing methods using the structure gauge provide an insufficient measure because the model either rotates or because the trajectory makes tight turns through narrow passages. This is the case in either automotive assembly lines or in narrow train tunnels.Objective: Given two point clouds, one of the environment and one of a model and a trajectory with six degrees of freedom along which the model moves through the environment, find all colliding points of the environment with the model within a certain clearance radius.Method: This paper presents two collision detection (CD) methods called kd-CD and kd-CD-simple and two penetration depth (PD) calculation methods called kd-PD and kd-PD-fast. All four methods are based on searches in a k-d tree representation of the environment. The creation of the k-d tree, its search methods and other features will be explained in the scope of their use to detect collisions and calculate depths of penetration.Results: The algorithms are benchmarked by moving the point cloud of a train wagon with 2.5 million points along the point cloud of a 1144 m long train track through a narrow tunnel with overall 18.92 million points. Points where the wagon collides with the tunnel wall are visually highlighted with their penetration depth. With a safety margin of 5 cm kd-PD-simple finds all colliding points on its trajectory which is sampled into 19,392 positions in 77 s on a standard desktop machine of 1.6 GHz.Conclusion: The presented methods for collision detection and penetration depth calculation are shown to solve problems for which the structure gauge is an insufficient measure. The underlying k-d tree is shown to be an effective data structure for the required look-up operations.     

Animated visualization of spatial–temporal trajectory data for air-traffic analysis

With increasing numbers of flights worldwide and a continuing rise in airport traffic, air-traffic management is faced with a number of challenges. These include monitoring, reporting, planning, and problem analysis of past and current air traffic, e.g., to identify hotspots, minimize delays, or to optimize sector assignments to air-traffic controllers. To cope with these challenges, cyber worlds can be used for interactive visual analysis and analytical reasoning based on aircraft trajectory data. However, with growing data size and complexity, visualization requires high computational efficiency to process that data within real-time constraints. This paper presents a technique for real-time animated visualization of massive trajectory data. It enables (1) interactive spatio-temporal filtering, (2) generic mapping of trajectory attributes to geometric representations and appearance, and (3) real-time rendering within 3D virtual environments such as virtual 3D airport or 3D city models. Different visualization metaphors can be efficiently built upon this technique such as temporal focus+context, density maps, or overview+detail methods. As a general-purpose visualization technique, it can be applied to general 3D and 3+1D trajectory data, e.g., traffic movement data, geo-referenced networks, or spatio-temporal data, and it supports related visual analytics and data mining tasks within cyber worlds.     

基于有向图的动态最优航迹规划算法

地形跟随/地形回避(TF/TA)航迹规划是低空突防系统的关键技术之一.通常所使用的动态规划算法得到的规划航迹有时达不到目标点.针对此问题,提出一种最优航迹规划的改进动态规划算法,通过对数字地图进行网格划分并建立有向图的方法改进动态规划算法,使最优航迹能有效地回避障碍和威胁.仿真结果表明,所提出的航迹规划算法是有效的.     

超宽带雷达的发展、现状及应用

超宽带雷达以其高距高分辩率、强穿透国、低截获率与强抗干扰性在军事、商业、环保等领域得到日益关注。本文综述了超宽带雷达的发展历史,结合国外实际超宽带合成孔径雷达系统阐明了超宽带合成孔径雷达的现状,并深入探讨了超宽带雷达的特性及其应用前景。超宽带雷达经过几十年的发展仍存在一些值得深入研究的问题,本文简要分析了部分技术难点,指出了超宽带雷达今后的发展和应用方向。     

多媒体技术在机场供油自动化系统中的应用

采用SCADA系统开发平台为民用机场供油自动化系统开发的监控管理应用软件具有非常友好的多媒体人机界面。该文对机场供油自动化系统的结构和功能做了简要的介绍,并着重介绍了多媒体人机界面的设计思路。该文所论述的多媒体人机界面设计方案被成功地应用于多个民用机场的供油自动化系统。