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基于模型检测的领域约束规划 总被引:13,自引:5,他引:8
基于模型检测的智能规划是当今通用的智能规划研究的热点,其求解效率比较高.但是,目前基于模型检测的智能规划系统没有考虑到利用领域知识来提高描述能力和求解效率.为此,研究了增加领域约束的基于模型检测的智能规划方法,并据此建立了基于模型检测的领域约束规划系统DCIPS(domain constraints integrated planning system).它主要考虑了领域知识在规划中的应用,将领域知识表示为领域约束添加到规划系统中.根据"规划=动作+状态",DCIPS将领域约束分为3种,即对象约束、过程约束和时序约束,采用对象约束来表达状态中对象之间的关系,采用过程约束来表达动作之间的关系,采用时序约束表达动作与状态中对象之间的关系.通过在2002年智能规划大赛AIPS 2002上关于交通运输领域的3个例子的测试,实验结果表明,利用领域约束的DCIPS可以方便地增加领域知识,更加实用化,其效率也有了相应的提高. 相似文献
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针对主干道信号灯通行可靠度不确定,难以定量分析的问题,提出基于模糊综合评价的主干道信号灯通行可靠度量化评估方法.结合Petri网构建主干道交叉口及车道模型,综合信号灯调控系统相位变化及实际应用条件,给出信号灯相位调控方案,并根据模糊控制理论对主干道车流量进行分类,引入疏解车距与等效车距得出主干道的车辆通行能力.计算与分析信号灯上、下段路径的通行能力匹配程度,采用综合模糊评价法,将车流通行的畅通程度作为通行可靠度量化评估指标,并给出评价集合与可靠度值,逐层运算后得到通行可靠度量化评估结果.分析实验结果得出,所设计方法具有较高的可行性,得到的评估结果对于车流管控与合理规划具有-定的参考价值. 相似文献
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仿真与建模是智能规划(特别是时态规划)走向应用的重要而困难的研究主题。目前已有的规划可视化建模工具只能支持领域无关的仿真和建模,无法模拟现实场景。基于时间线的Chronicle规划与Microsoft最新的图形显示技术WPF在某些概念上存在自然的对应关系。基于这样的思想,针对NASA开发的开源时态规划平台——Europa2,使用WPF基础类库和相关工具,研究智能规划能够模拟现实场景的动态仿真和建模的设计方法并给出了实例演示。研究表明,对诸如Europa2一类基于时间线的Chronicle规划系统,可以应用WPF一类通用图形技术进行方便的建模和动态仿真,从而初步解决了规划系统模拟现实场景的仿真和建模难以实现的问题。 相似文献
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导弹集群协同作战是C4ISR的网络攻击的典型作战模式,本文以无人机中继模式为例分析了导弹集群实施远程打击的作战流程。任务规划系统的关键技术包括网络体系下的系统结构、任务调度技术、实时航路规划技术、人在回路制导方式下导弹饱和攻击技术等。设计了导弹集群任务规划仿真系统,主要功能包括:任务管理、地图预处理、数据链信息处理、任务规划、视景仿真等。导弹集群协同航路规划子系统是任务规划系统的重要子系统,对其系统结构进行了分析与设计,并给出了航路规划的仿真结果。 相似文献
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一种基于成本控制的GSM网络智能规划系统 总被引:1,自引:0,他引:1
在遗传算法(Genetic Algorithm)的基础上提出了一种基于成本控制的GSM网络规划算法,并在此基础上设计实现了一种面向成本控制的GSM网络智能规划系统。仿真和实际应用表明,该规划系统综合考虑了在GSM网络规划实际工程中的多种规划目标和要求,能够找到符合GSM网络运营商要求的成本最低方案。 相似文献
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周瑜 《数码设计:surface》2021,(7):28-28
无人机任务规划系统是指配装在地面或是飞机上,用来对不同类型数量的无人机进行任务分配、航路规划的一种规划系统。本文首先介绍了无人机任务规划的概念,并说明了无人机任务规划系统的特点。再详细介绍外军无人机任务规划系统的发展情况。 相似文献
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车联网的通信密钥管理水平决定其信息保密性和抵御电子欺骗等基于用户身份的攻击的安全性。现有密钥管理方案采用固定频率更新车联网的群密钥,增大了密钥更新时延和加密时延。提出一种基于强化学习的低时延车联网群密钥分配管理技术,令群首车辆根据周边车辆数目变化和密钥更新记录等因素优化其群密钥的更新频率和密钥长度。该技术不需要群首车辆预知附近的车流变化模型与访问驱动高速缓存攻击模型,降低加解密时延,并在基于高级加密标准的车联网仿真进行验证。仿真结果表明,相比基准的群密钥管理方案,该技术降低密钥更新的传输时延,减少车联网的加解密计算时延,并提高群密钥的保密性。 相似文献
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《Computer Networks》2008,52(5):957-970
We propose a router-based technique to mitigate the stealthy reduction of quality (RoQ) attacks at the routers in the Internet. The RoQ attacks have been shown to impair the QoS sensitive VoIP and the TCP traffic in the Internet. It is difficult to detect these attacks because of their low average rates. We also show that our generalized approach can detect these attacks even if they employ the source IP address spoofing, the destination IP address spoofing, and undefined periodicity to evade several router-based detection systems. The detection system operates in two phases: in phase 1, the presence of the RoQ attack is detected from the readily available per flow information at the routers, and in phase 2, the attack filtering algorithm drops the RoQ attack packets. Assuming that the attacker uses the source IP address and the destination IP address spoofing, we propose to detect the sudden increase in the traffic load of all the expired flows within a short period. In a network without RoQ attacks, we show that the traffic load of all the expired flows is less than certain thresholds, which are derived from real Internet traffic analysis. We further propose a simple filtering solution to drop the attack packets. The filtering scheme treats the long-lived flows in the Internet preferentially, and drops the attack traffic by monitoring the queue length if the queue length exceeds a threshold percent of the queue limit. Our results show that we can successfully detect and mitigate RoQ attacks even with the source and destination IP addresses spoofed. The detection system is implemented in the ns2 simulator. In the simulations, we use the flowid field available in ns2 to implement per-flow logic, which is a combination of the source IP address, the destination IP address, the source port, and the destination port. We also discuss the real implementation of the proposed detection system. 相似文献
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Filtering out traffic with forged source address on routers can significantly improve the security of Internet. However, despite intermittent IP spoofing attacks, existing filtering mechanisms inspect each packet all the time, consuming considerable resource on routers even there is no spoofing at all. This article considers the requirement for a solution performing IP spoofing filtering with agility, which consumes resource in proportional to the size of attack. A novel IP spoofing filtering mechanism named Virtual Anti-Spoofing Edge (VASE) is proposed in this article. VASE uses sampling and on-demand filter configuration to reduce unnecessary overhead in peace time. The evaluation based on simulation shows VASE has obvious advantages over commonly used mechanisms in various scenarios. VASE is fully compatible with current IP spoofing filtering practices and can be implemented with commodity routers. In the campus network of Tsinghua University, VASE is providing real benefits. 相似文献
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DNS是目前大部分网络应用的基础,对它的攻击将影响整个Internet的正常运转。DNS欺骗攻击是攻击者常用的手法,它具有隐蔽性强、打击面广、攻击效果明显的特点,但是目前对这种攻击还没有好的防范策略。该文分析了DNS协议的工作原理,讨论了DNS协议在Internet中欺骗的实现,最后提出了一些检测和防范的措施。 相似文献
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DDoS(Distributed Denial of Service)攻击是在传统的DoS攻击上产生的新的网络攻击方式,是Internet面临的最严峻威胁之一,这种攻击带来巨大的网络资源消耗,影响正常的网络访问.DDoS具有分布式特征,攻击源隐蔽,而且该类攻击采用IP伪造技术,不易追踪和辨别.任何网络攻击都会产生异常流量,DDoS也不例外,分布式攻击导致这种现象更加明显.主要研究利用神经网络技术并借助IP标记辅助来甄别异常流量中的网络数据包,方法是:基于DDoS攻击总是通过多源头发起对单一目标攻击的特点,通过IP标记技术对路由器上网路包进行标记,获得反映网络流量的标记参数,作为神经网络的输入参数相量;再对BP神经网络进行训练,使其能识别DDoS攻击引起的异常流量;最后,训练成熟的神经网络即可在运行时有效地甄别并防御DDoS攻击,提高网络资源的使用效率.通过实验证明了神经网络技术防御DDoS攻击是可行和高效的. 相似文献
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Improvement of the secure dynamic ID based remote user authentication scheme for multi-server environment 总被引:2,自引:0,他引:2
Recently, Liao and Wang proposed a secure dynamic ID based remote user authentication scheme for multi-server environment, and claimed that their scheme was intended to provide mutual authentication, two-factor security, replay attack, server spoofing attack, insider and stolen verifier attack, forward secrecy and user anonymity. In this paper, we show that Liao and Wang's scheme is still vulnerable to insider's attack, masquerade attack, server spoofing attack, registration center spoofing attack and is not reparable. Furthermore, it fails to provide mutual authentication. To remedy these flaws, this paper proposes an efficient improvement over Liao–Wang's scheme with more security. The computation cost, security, and efficiency of the improved scheme are well suited to the practical applications environment. 相似文献