共查询到19条相似文献,搜索用时 109 毫秒
1.
2.
3.
认知无线网络是一种开放性的智能网络,通过网络环境的学习分析,对网络状态进行规划、决策和响应。认知无线网络使网络从静态工作模式发展到动态自适应工作模式,从单一封闭式网络发展到异构融合网络,是解决网络容量受限,实现频谱高效利用和异构网络融合的有效途径之一。认知无线网络的相关研究在国家973项目的支持和项目组各单位的共同努力下取得了长远发展,主要讨论认知无线网络架构的理论模型、实现功能以及部署实现,然后分析了支撑架构的关键技术研究,主要包括多域主动认知方法、自主资源决策管理、无线自主传输机制以及体系结构适变技术等。 相似文献
4.
5.
6.
7.
8.
文章提出支持应急通信的认知网络体系结构与模型,以及在此基础上涉及的认知模型服务质量控制和优化策略、智能决策和学习算法,目标在于通过对网络环境状态的观察和学习,智能决策并自适应调整节点行为,进而达到对网络性能的优化。 相似文献
9.
为克服无线网络的窄带宽和移动计算终端固有的功耗较低与资源有限等缺陷,提出了一种无线网络环境下基于视觉优化的多分辨率三维模型传输与实时绘制方法。首先,基于改进显著性区域计算模型提出一种视觉优化的模型简化算法,使视觉重要顶点在简化过程中尽可能地得到保留。在该计算模型中,提出了一种三维本地窗口计算方法和加权融合技术以获得有效样本顶点,提高了显著性区域判定的准确性。其次,提出一种无线网络中模型实时绘制方法,通过有效的模型编码和计算任务分配,使渐进模型数据能够快速传输到移动客户端,并在仅进行基本绘制计算的同时摒弃耗费资源的本地重构计算。最后,分别在模拟环境和在802.11b标准的无线局域网络环境中进行了算法性能测试。实验结果表明,采用本算法能够在获得较好的模型视觉简化效果的同时实现模型的任意分辨率的实时绘制。 相似文献
10.
在认知抗干扰通信系统中,智能决策是其核心,根据干扰环境,对系统的干扰抑制方式、频谱资源分配、调制编码方式和功率调整信息进行最优决策。现有的抗干扰通信系统的智能决策多采用遗传算法、人工蜂群算法等,面对日益复杂的电磁环境,通常这些算法不具有对新干扰的泛化能力。BP神经网络算法简单、具有一定的容错能力和泛化能力,本文设计并分析了一种基于BP神经网络的抗干扰实时决策引擎模型,根据系统性能设计了输入输出数据的预处理方式和判别标准,阐述了决策实现步骤,分析了算法参数;通过系统性能仿真,验证了文中提出的实时决策引擎的强抗干扰性能。与采用遗传算法和人工蜂群算法的决策引擎相比,本文提出的决策引擎决策速度更快且具有泛化能力和容错能力。 相似文献
11.
Facing to the challenges of dynamic adaptation capabilities in the time-varying environment of cognitive radio networks (CRN), reconfiguration capabilities are introduced to flexibly and dynamically adapt to changing wireless environment and service requirement. As one of the essential characteristics for CRN, the cognitive reconfiguration can meet the user requirements, realize interoperability between heterogeneous networks, make full use of radio resources and adapt to the time-varying environment to achieve the end-to-end requirements. However, the reconfiguration implementation is still challenging due to its need for complex environment cognition and multi-objects optimization. In this direction, ant colony optimization(ACO) technique, as an intelligent technology to solve the complex issues, is introduced to the appropriate model of the reconfiguration decision making process to achieve the adaption alternatives. The aim of this paper is to present a generic cognitive reconfiguration framework including indispensable function entities for autonomous reconfiguration decision making with regard to the multiple and complex objectives. Moreover, three kinds of reconfiguration approaches, which are parameters reconfiguration, radio resource reconfiguration and heterogeneous access reconfiguration, are proposed. Finally, numerous results prove the effective performance improvements of ACO based reconfiguration solution in CRN. 相似文献
12.
Cognitive radio is a technological concept pushing for the introduction of intelligent radio operation that goes beyond traditional system adaptation. So far, a rather limited amount of work has been published on the cognitive mechanisms that should be embedded into communicating equipments to achieve such an intelligent behavior. This paper presents a generic cognitive framework for autonomous decision making with regard to multiple, possibly conflicting, operational objectives in a time-varying environment. The framework is based on the definition of two scales introducing order relationships between the configurations that help the reasoning and learning processes. The resulting cognitive engine learns to progressively identify the optimal configurations for the design objectives imposed given the current radio environment. The proposed approach is illustrated for a case of cognitive waveform design and extensive simulation results validate the cognitive engine behavior. 相似文献
13.
为了有效地缩短配电网络重构的时间,首先对BP神经网络从学习速度和局部收敛方面改进,以提高BP算法的速度,然后根据配电网的数学模型,在BP神经网络的误差函数和约束条件的分析中运用图论知识,从而准确并快速地实现配电网络重构. 相似文献
14.
15.
贝叶斯网络是数据挖掘领域的主要工具之一。在某些特定场合,如重大装备的故障诊断、地质灾害预测及作战决策等,希望用少量数据得到较好的结果。因此,本文针对小数据集条件下的贝叶斯网络学习问题展开研究。首先,建立基于连接概率分布的结构约束模型,提出I-BD-BPSO(Improved-Bayesian Dirichlet-Binary Particle Swarm Optimi-zation)结构学习算法;其次,建立单调性参数约束模型,提出MCE(Monotonicity Constraint Estimation)参数学习算法;最后,应用所提算法构建威胁评估模型并应用变量消元法进行推理计算。实验结果表明,在小数据集条件下,本文的结构学习算法优于经典的二值粒子群优化算法,参数学习算法优于最大似然估计、保序回归及凸优化算法,并能够构建有效的威胁评估模型。 相似文献
16.
Cognitive networks are capable of learning and reasoning. They can dynamically adapt to varying network conditions in order to optimize end-to-end performance and utilize network resources efficiently. This paper proposes a cognitive network routing scheme that includes a context information collection entity,a route manager entity,a route reconfiguration entity,and reasoning and learning entity. 相似文献
17.
The self-adaptation of software systems is a complex process that depends on several factors that can change during the system operational lifetime. But, Today’s workflow management systems are only applicable in a secure and safe manner if the business process to be supported is well-structured and there is no need for ad hoc deviations at runtime. Hence, it is necessary to define mechanisms for providing a self-adaptive system the capability of reconfiguration during run-time the process that controls its adaptation. In this paper, we provide rapid dynamic reconfiguration using the workflow based on goal-scenario as the basis to set up strategies in accordance with the adaptive judgment. Also, we provide a sophisticated approach which fosters learning from past process changes by process variants through the order matrix. We present a formal foundation for the support of dynamic structural workflow changes of running. Our approach uses estimates based goal-scenario to determine which remaining parts of running workflows are affected by the external environment and is able to predictively perform suitable adaptation. This helps to ensure that necessary adaptation are performed in time with minimal user interaction which is especially valuable in change of external environment. 相似文献
18.
19.
为了克服传统专家系统知识获取难、学习适应能力差、推理效率低等问题,许多专家提出将神经网络与规则专家系统相结合,构建基于神经网络的专家系统模型。文中设计了一种基于神经网络专家系统模型的混合推理机制,通过对基于神经网络推理算法、规则推理算法以及神经网络与规则的混合推理算法进行实验比较,证明本文提出的混合推理机制在改善专家系统推理准确率方面的有效性。 相似文献