基于SAR辅助的惯导/星光组合导航系统研究

针对高空、长航时无人飞行器在对地观测成像期间对导航自主性和高精度的需求,研究了基于SAR辅助的惯导/星光姿态组合导航系统.针对SAR图像导航输出的间断性和多传感器组合导航系统中量测输出的不同步特性,设计了解决非连续性量测修正的多传感器组合导航滤波器模型.提出了解决多传感器量测不同步问题的异步集中滤波算法.仿真结果表明:...     

Asynchronous double-precision windows based unmanned aerial vehicle real-time path planning

A real-time path planning approach based on asynchronous double-precision windows is proposed for unmanned aerial vehicles (UAVs). In this proposed method, cursory paths and elaborate paths are planned respectively in the global and local windows. Specifically, global cursory path planner and local elaborate path planner are integrated by rolling two windows on different frequencies with different modes. Simulation results demonstrate that the proposed approach is effective for realizing a balance between t...     

基于P／S模式的分布对象中间件异步通信接口

对分布对象中间件异步通信中的时间、空间和流程的解耦问题进行研究,分析当前分布对象中间件异步通信机制存在的问题。基于CORBA分布环境引入P／S发布订阅系统,构建基于P／S模式的CORBA通信体系。阐述该通信体系的体系结构及其接口的封装与设计,对支持这种通信体系的使能技术进行说明。     

异步128位AES算法的硬件设计

基于四相握手协议设计异步流水线,实现单轮运算内流水操作,设计轮运算启动模块和异步控制信号生成模块,满足算法多轮运算的需要。在子密钥生成模块、字节替代模块和列混合模块使用复用技术,降低了对硬件的需求。在COMS0.18μm工艺下进行综合、布局布线和仿真,与采用同样数据路径设计方法的同步电路相比,吞吐率提高了12.5%。     

基于PLC的50 kV三相耐压测试系统

根据电气设备高、低压试验要求,鉴定试品耐高压冲击性能和耐高压能力,设计了以PLC为主控设备、以LabVIEW为上位机软件的交流耐压测试系统.本系统由调压器、扼流电感以及变压器组成,由上位机设置任务参数并由PLC采用符号判别法控制系统输出,对试品进行耐压测试.测试数据表明该系统具有较高的电压控制精度,满足工频耐压鉴定需求,具有较好的应用前景,为高压设备耐压测试提供了一种有益的技术参考.     

Robust stabilisation and L2 -gain analysis for switched systems with actuator saturation under asynchronous switching

Robust stabilisation and L₂-gain analysis for a class of switched systems with actuator saturation are studied in this paper. The switching signal of the controllers lags behind that of the system modes, which leads to the asynchronous switching between the candidate controllers and the subsystems. By combining the piecewise Lyapunov function method with the convex hull technique, sufficient conditions in terms of LMIs for the solvability of the robust stabilisation and weighted L₂-gain problems are presented respectively under the dwell time scheme. Finally, a numerical example is given to demonstrate the feasibility and effectiveness of the proposed results.     

视觉P300脑机接口中的SOA扰动现象

异步操控性是脑机接口走向实际应用的关键技术之一.其关键点在于寻找一种可有效区分脑机接口工作状态和空闲状态的指标.建立了针对P300脑机接口的刺激起始异步(SOA)扰动模型,在仿真实验和实测数据中观察到SOA扰动谱线,并根据所提出的模型给出了合理解释.研究了SOA扰动的频域特性,结果表明,当SOA位于220 ms附近时,SOA扰动的强度最大,而当SOA低于150 ms时,SOA扰动强度将急剧减小.同时SOA扰动所具有的锁相性使得可以通过时域相干平均法进一步提高信噪比.SOA扰动可作为脑机接口处于工作状态的标志,为异步脑机接口的实现提供了一种新的研究思路.     

基于微机的安控台技术研究

安控台是靶场试验中的重要装备,可靠性要求高,构成复杂,不适于移动式快速使用。同时,异步数据检测是靶场测控系统调试的重要内容,为了方便检查遥控站状态和指令收发功能,使用VC++编程语言在微机上实现了安控台与遥控站之间异步串行通信功能,提高了遥控站的异步数据检测速度,扩展了遥控站的维护范围。     

模糊系统的微粒群并行聚类算法

为了解决大规模的数据聚类问题时需要的大量计算,提出了一种模糊系统的微粒群优化并行k-means聚类算法。该方法利用模糊规则,动态地调整微粒群惯性权重和加速因子,克服群体逐渐失去迁移性而停止进化的问题,保证群体多样性而避免陷入局部极小值。采用任务并行和部分异步通信模式,降低计算时间。实验结果表明,该算法在并行机群上运行时,加快了聚类算法的计算速度,提高了聚类质量。     

Adoption of Asynchronous Learning Tools by Traditional Full-Time Students: A Pilot Study

Comparing the performance of distance learning and on-campus students is a well-studied problem. Results have shown that distance learners can perform as well or better than on-campus students. Few studies, however, have explored how or why traditional on-campus students utilize the technology intended for distance learners. Many universities and corporations provide educational and training content simultaneously to both face-to-face and distance students. Thus, exploring how instructional technology typically designed for distance learning students could benefit traditional students is important to our understanding of present and future learning environments. To this end, a pilot study was undertaken that explored how graduate students – primarily business majors – adopted and used video-streaming technology for a one semester course on Knowledge Management Tools and Techniques. Results indicated that age, previous use of the technology, need for interaction and Internet connectivity all influenced the decisions of the subjects to adopt the technology. Two-thirds of the subjects used the technology, with a self-reported estimate of procuring 16% of the course content asynchronously. Most used video streaming for convenience reasons and to review class material.