基于IPv6组播的M-FHM IPv6切换技术

由于快速分层切换技术FHMIPv6将FMIPv6和HMIPv6切换技术结合起来,因此,在层次移动管理模型中部署快速切换时具有两种技术所具有的优点,可使切换延时进一步减少。文中通过对FHMIPv6的研究发现,其切换过程中DAD重复地址检测过程严重影响了切换性能,因此提出了基于IPv6组播的M-FHMIPv6切换技术。理论分析证明,M-FHMIPv6能有效减少DAD检测过程和各种信息交互的延迟。通过NS2实验仿真进一步说明:改进的M-FHMIPv6方案能减少切换延迟,平滑切换过程。     

基于跨层快速邻居感知的OLSR协议

提出了一种基于跨层快速邻居感知的OLSR协议——FS-OLSR,协议在采用hello消息进行链路感知和邻居探测的基础上,结合链路层反馈的信息对网络层邻居表进行更新,以增强节点的邻居感知能力;并将邻居节点的新鲜度作为MPR计算的依据,以提高拓扑消息中广播邻居节点的新鲜度,使之更加适合于快速移动场景。仿真结果表明,在快速移动场景中,FS-OLSR能够在增加少量路由开销的情况下,显著降低丢包率。     

快速模式匹配在网络教育平台中的应用研究

网络教育平台建设的核心是教学资源库的建设,各种类型资源的快速匹配是需要频繁使用的基础功能。现有的解决方案往往使用的是BF等经典算法,匹配效率有一定的提高空间。用XML技术作为平台中各种资源描述的统一工具,通过对XML技术中DTD模式匹配方法的研究以及对模式匹配快速算法的改进,提高模式匹配的效率,从而设计出一种有效的信息模式匹配技术模型。通过仿真实验表明该模型可有效地提高网络教育平台中信息匹配的效率,进而为平台中资源的整合与模式的统一提供支持。     

Deconvolution with partially known kernel of nonnegative signals

This paper extends the Bayesian direct deconvolution method to the case in which the convolution kernel depends on few unknown nuisance parameters. Moreover, an acceleration procedure is proposed that drastically reduces the computational burden. Finally, the implementation of the method by means of the fast Fourier transform is fully discussed in the multidimensional case.     

Contrast‐enhanced wide‐angle high‐speed polarization modulator for active‐retarder 3‐D displays

Abstract— A contrast‐enhanced wide‐angle high‐speed polarization modulator for active‐retarder 3‐D displays is proposed. By using a double liquid‐crystal‐cell structure together with a dedicated driving scheme and an external quarter‐wave retarder, a high‐performance modulator can be realized, resulting in minimized brightness loss and low cross‐talk levels in fast‐refresh time‐multiplexed 3‐D displays.     

双向准Z源逆变器驱动永磁同步电机的快速有限集模型预测控制

双向准Z源逆变器驱动永磁同步电机(PMSM)系统在兼具Z源逆变器和PMSM优点的同时,还可实现能量的双向流动。针对双向准Z源逆变器驱动PMSM系统的特点,提出一种快速矢量选择有限集模型预测电流控制(FCS\|MPCC)策略。由双向准Z源网络直流链电压闭环与PMSM电磁功率前馈生成电感电流参考值,由电机转速闭环生成电机电流参考值。通过预测直通(ST)及非直通(NST)状态下的电感电流值并引入电感电流子代价函数以确定是否选择ST状态,进而实现对直流链电压的控制。在NST状态下,结合空间电压矢量脉宽调制策略,仅使目标电压矢量所在扇区的4个矢量参与PMSM定子电流预测和代价函数计算,以选择最优的开关状态,在实现对PMSM转速控制的同时减小在线计算量。仿真结果表明,所提控制策略可实现对双向准Z源逆变器的升压及PMSM牵引或制动工况下的转速控制,系统具有良好的稳态及动态性能。     

基于SWT的GIS电压互感器二次侧干扰分析

特快速暂态过电压（VFTO）是气体绝缘变电站（GIS）中切换隔离开关时产生的特殊电磁暂态现象。VFTO会以传导和辐射方式影响二次设备的正常运行。为探究VFTO对二次设备的干扰特性,文中采用自制的二次侧干扰测量装置对某1 000 kV GIS的电压互感器（PT）二次侧共模干扰进行现场实测。接着,对比了5种时频分析方法的性能,采用其中性能较优的同步压缩小波变换（SWT）对实测波形进行了时频分析。实测结果表明：PT二次侧的共模干扰电压峰峰值最高可达9.65 kV。微脉冲的时频分析结果表明：7.8 MHz频率分量幅值高,且贯穿波形的始终,是PT二次侧干扰的主导频率分量。该分析结果可为GIS中二次设备的电磁抗扰度测试和电磁防护设计提供参考。     

Dynamic compensation by fusing a high-speed actuator and high-speed visual feedback with its application to fast peg-and-hole alignment

This paper presents a dynamic compensation concept to grapple with the dynamic defects of a traditional robot arm, especially while performing high-speed endpoint regulations. The proposed high-speed dynamic compensation concept offers a new point of view for cooperating with a traditional manipulator to realize highly dexterous performance of manipulations. The concept is realized through adoption of a high-speed light-weight actuator as well as endpoint closed loop configured high-speed cameras. The dynamic compensation is analyzed experimentally with 1000 Hz visual feedback and a high-speed finger for a robot arm in the case of one degree of freedom. The advantage of the proposed approach is that the modeling for the robot system’s dynamics is not needed, whereas it is necessary and trivial in order to realize high-speed regulations by traditional approaches. Thus, the control issue becomes easier with the proposed approach. As an application for this concept, fast peg-and-hole alignment with large position and attitude uncertainty is studied. The alignment algorithm is based on a visual compliance strategy. Alignment experiments show that with the proposed concept of dynamic compensation as well as visual compliant motion control, robust and fast convergence was realized for most cases.     

基于局部自适应先验MRF模型的快速BP图像分割算法

针对常规MRF分割模型不能有效描述图像的局部特征、常导致图像的过分割现象,提出了一种局部自适应先验的MRF模型。该模型利用图像的邻接区域信息建立了一种局部自适应特征MRF模型。基于提出的模型,建立了一种具有快速收敛策略的区域BP算法对MRF模型的区域消息进行传递,有效解决了区域BP算法的计算量大的问题。实验结果表明,与常规区域BP算法相比,提出的分割方法具有更快的分割速度和精度。     

NH3-NO/NO2 SCR for diesel exhausts after treatment: mechanism and modelling of a catalytic converter

We review herein the key mechanistic and kinetic features of the reactions involved in the NH₃-NO/NO₂ SCR system investigated by dynamic reactive experiments over a V-based commercial powdered catalyst, eventually leading to the proposal of an original redox scheme which accounts for stoichiometry, selectivity and intrinsic kinetics of the global SCR process.