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面向IP快速路径切换的OSPF冗余路径算法 总被引:1,自引:0,他引:1
在IP网络中,当某链路或者节点发生故障时,通过路由协议的收敛来绕开故障的链路或节点.对OSPF路由协议,这个时间至少为5秒,期间经过故障节点或链路的流量将会被丢弃,绝大多数的应用可以承受这种程度的延迟.但是,对延迟敏感的应用如VoIP而言,这种量级的延迟是很难为用户所接受的.基于现有的OSPF路由协议的最短路径树(SPT)算法,提出一种支持IP快速重路由的多冗余路径树计算算法.算法计算除最短路径外至少一条不相交无环备份路径,保证在最短路径的链路或节点故障时,通过快速切换到备份路径,以提高IP网络的故障收敛时间. 相似文献
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We consider multilabel classification problems where the labels are arranged hierarchically in a tree or directed acyclic graph (DAG). In this context, it is of much interest to select a well-connected subset of nodes which best preserve the label dependencies according to the learned models. Top-down or bottom-up procedures for labelling the nodes in the hierarchy have recently been proposed, but they rely largely on pairwise interactions, thus susceptible to get stuck in local optima. In this paper, we remedy this problem by directly finding a small number of label paths that can cover the desired subgraph in a tree/DAG. To estimate the high-dimensional label vector, we adopt the advantages of partial least squares techniques which perform simultaneous projections of the feature and label space, while constructing sound linear models between them. We then show that the optimal label prediction problem with hierarchy constraints can be reasonably transformed into the optimal path prediction problem with the structured sparsity penalties. The introduction of path selection models further allows us to leverage the efficient network flow solvers with polynomial time complexity. The experimental results validate the promising performance of the proposed algorithm in comparison to the state-of-the-art algorithms on both tree- and DAG-structured data sets. 相似文献
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针对自动跟随小车实际工作环境下目标点和障碍物具有可移动特征,在传统人工势场法的基础上提出一种具有动态路径预测功能的路径规划方法。通过实时采集和计算小车、目标点和障碍物的距离、运动速度和方向,预测未来三者之间可能的位置关系。根据目标点预测结果采用人工势场法确定接近目标点路径,根据预测的障碍点运行轨迹确定绕过障碍点的路径。将基于路径预测人工势场法与传统人工势场法进行仿真对比,结果表明该方法在跟随效率和避障能力上具有显著的提高。 相似文献
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多数观点动力学研究采用基于Agent的建模和仿真方法,与现实社会现象严重脱节。针对该问题,利用现实社会在线评分的统计数据验证和改进观点动力学模型的解释和预测能力。在评分过程中,个体的观点受到自身初始观点和群体观点的共同影响,产生的最终观点将决定个体是否加入评分群体,如果加入将产生评分行为,进而影响后续个体的观点及行为。据此过程建立一个连续观点动力学模型,对在线评分的人员数量进行预测。使用豆瓣网站的影片在线评分数据进行实验,分析各评分观点变化对在线评分数量的影响,结果表明,该模型能够有效预测在线评分人数;个体的最终观点主要受群体差-中-好评分观点的影响,而与自身初始观点基本无关;泊松参数值偏离最优值越远,预测准确率越低。 相似文献
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《Automatic Control, IEEE Transactions on》2009,54(1):34-47
This paper is concerned with persistent identification of systems that involve deterministic unmodeled dynamics and stochastic observation disturbances, and whose unknown parameters switch values (possibly large jumps) that can be represented by a Markov chain. Two classes of problems are considered. In the first class, the switching parameters are stochastic processes modeled by irreducible and aperiodic Markov chains with transition rates sufficiently faster than adaptation rates of the identification algorithms. In this case, tracking real-time parameters by output observations becomes impossible and we show that an averaged behavior of the parameter process can be derived from the stationary measure of the Markov chain and can be estimated with periodic inputs and least-squares type algorithms. Upper and lower error bounds are established that explicitly show impact of unmodeled dynamics. In contrast, the second class of problems represents systems whose state transitions occur infrequently. An adaptive algorithm with variable step sizes is introduced for tracking the time-varying parameters. Convergence and error bounds are derived. Numerical results are presented to illustrate the performance of the algorithm. 相似文献
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基于未建模动态补偿的非线性自适应切换控制方法 总被引:1,自引:0,他引:1
针对一类不确定的离散时间零动态不稳定的单输入-单输出(Single-input single-output, SISO)非线性系统,提出了一种基于未建模动态补偿的非线性控制器. 采用自适应神经模糊推理系统(Adaptive-network-based fuzzy inference system, ANFIS)和一一映射相结合的方法估计未建模动态.在此基础上,提出了由线性自 适应控制器、非线性自适应控制器以及切换机制组成的自适应切换控制方法.该方法通过对上述两种控制器的切换, 保证闭环系统输入输出信号有界的同时,改善系统性能.本文将要求未建模动态全局有界的条件放宽为线性增长, 建立了所提自适应控制方法的稳定性和收敛性分析.通过仿真比较和水箱的液位控制实验,验证了所提方法的有效性. 相似文献
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台风路径实质为二维平面上一段曲线,根据2条台风路径曲线的相似度可以判断其数值相似和形态相似,由此利用动态规整算法可以从历史台风数据库筛选出与目标台风相似的台风路径。同时考虑到台风路径信息的时间关联性,提出了长短时记忆网络预测模型。利用历史台风的经纬度信息,预测台风未来6小时位置信息,对比传统基于相似度预测台风路径方法,长短时记忆模型能够有效提高台风路径预测精度,模型更加稳定高效。 相似文献
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针对多无人机(Unmanned Aerial Vehicles, UAVs)协同控制问题,提出了一种UAVs多阶段航迹预测分布式任务规划方法;定义从一次任务分配开始到其中一项任务完成为一个任务周期;在每个规划周期,首先,各UAV使用A*算法快速预测到所有任务目标的路径,提供至任务分配;然后,采用聚类算法修改目标价值向量,协商分配结果,并实时计算探测范围内的最短路径;最后,采用三次B样条曲线平滑所分配的最短路径,在线规划出满足飞行约束的飞行航迹;通过仿真实验对算法的有效性进行了验证,结果表明,提出的算法能够实时获得近似最优的任务分配结果并规划出可飞行航迹,并有效处理突发任务。 相似文献
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Neural Short-Term Prediction Based on Dynamics Reconstruction 总被引:2,自引:0,他引:2
In this paper we present an application of dynamics reconstruction techniques to model order estimation. Both the Grassberger–Procaccia and the Takens' method were applied, yielding similar values for the correlation dimension, hence for the model order. Based on this model order, appropriately structured neural nets for short-term prediction were designed. Satisfactory experimental results were obtained in one-hour-ahead electrical load forecasting on a six-month benchmark from an electric utility in the U.S.A. 相似文献
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利用自主式水下航行器(Autonomous Underwater Vehicle,AUV)对水下多目标进行协同探测是目前海洋技术领域的研究热点.主要研究在水下三维区间内的多AUV任务分配与协作探测路径规划机制,建立了以每个AUV能量耗费与能耗均衡为约束条件的水下三维空间中的多旅行商MTSP(Multiple Traveling Salesman Problem)问题模型,利用遗传算法GA(Genetic Algorithm)对该NP-Complete问题进行启发式求解,同时设计了考虑巡航总路径及访问目标数的适应度函数以提高多AUV间的能耗均衡性,实现多个AUV对多个水下目标的优化协同探测.最后本文利用MATLAB R2014a软件对多AUV任务协作与多目标探测路径规划机制进行了仿真,仿真结果验证了本文方法能均衡多AUV多目标探测问题的能量消耗,进而提高巡航速度和生命周期. 相似文献
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基于航迹预测的飞行冲突探测 总被引:1,自引:0,他引:1
基于飞行器飞行途中的随机影响及观测仪器的误差影响,给出了常速模型的冲突探测模型。重点讨论2架飞行器靠近飞行的情况,采用卡尔曼滤波理论,预测2架飞行器的相对航迹。然后依据相对航迹,计算2架飞行器在各时刻的距离。最后根据冲突条件判断冲突是否存在。该方法不仅从模型上保证了更接近飞行器的实际飞行情况,而且计算机仿真结果表明该方法能有效地进行冲突探测。 相似文献