Video summarization via minimum sparse reconstruction

The rapid growth of video data demands both effective and efficient video summarization methods so that users are empowered to quickly browse and comprehend a large amount of video content. In this paper, we formulate the video summarization task with a novel minimum sparse reconstruction (MSR) problem. That is, the original video sequence can be best reconstructed with as few selected keyframes as possible. Different from the recently proposed convex relaxation based sparse dictionary selection method, our proposed method utilizes the true sparse constraint L₀ norm, instead of the relaxed constraint _L2,1$L_{2,1}$ norm, such that keyframes are directly selected as a sparse dictionary that can well reconstruct all the video frames. An on-line version is further developed owing to the real-time efficiency of the proposed MSR principle. In addition, a percentage of reconstruction (POR) criterion is proposed to intuitively guide users in obtaining a summary with an appropriate length. Experimental results on two benchmark datasets with various types of videos demonstrate that the proposed methods outperform the state of the art.     

电力巡线无人机数据传输系统研究

针对无人机数据链系统需要同时传输不同类型信息而且其性能指标迥异的问题,提出了安全性非对称信息一体化传输技术。该技术采用直接序列扩频技术对遥测等重要数据进行附加保护,与图像数据复接后统一进行QPSK调制,解决了直接复接技术可靠性不足、UQPSK功率分配灵活性差的问题,实现了多类型信息的差别复合传输。仿真结果表明,在改善频带利用率的同时,提高了重要信息链路的接收信噪比,与理论分析一致。     

低成本MEMS陀螺实时滤波方法

为找到一种普遍适合低成本MEMS陀螺仪的随机误差实时处理方法,利用Allan方差分析法首先对MEMS陀螺仪进行分析,根据其误差特性进而设计了平均滤波算法以剔除粗大误差,然后使用最小二乘法,通过拟合前一段历史结果得到下一时刻输出的预测值,基于以上工作最终设计出Kalman滤波器对所输出进行滤波。由于将最小二乘法的推测作为预测过程,避免了系统状态模型难以准确建立的问题。该方法动态性能好,具有普适性。实验结果证明,该方法在静态和动态下均能有效工作,滤波后常值漂移被有效补偿,角度随机游走不再占误差的主要成分,均方差小于滤波前的十分之一。     

基于TMS320C6678的多核程序加载研究与实现

针对多核D SP系统程序加载复杂的问题,基于T MS320C6678对多核程序加载进行了研究与设计。从一级引导程序出发,设计并优化了多核程序内容存储格式。设计了简洁的二级引导程序,以修正一级引导程序只识别主核程序入口地址,而从核入口地址缺失的现象。为了快速生成特定格式的多核程序内容,设计了多个工具用于添加S PI启动参数表、DDR3启动表、从核程序入口地址以及完成程序内容格式的转换。实现了S PI Flash多核程序加载以及基于I2C主模式的Nand Flash多核程序加载。     

Nonlocal variational image segmentation models on graphs using the Split Bregman

Variational functionals such as Mumford-Shah and Chan-Vese methods have a major impact on various areas of image processing. After over 10 years of investigation, they are still in widespread use today. These formulations optimize contours by evolution through gradient descent, which is known for its overdependence on initialization and the tendency to produce undesirable local minima. In this paper, we propose an image segmentation model in a variational nonlocal means framework based on a weighted graph. The advantages of this model are twofold. First, the convexity global minimum (optimum) information is taken into account to achieve better segmentation results. Second, the proposed global convex energy functionals combine nonlocal regularization and local intensity fitting terms. The nonlocal total variational regularization term based on the graph is able to preserve the detailed structure of target objects. At the same time, the modified local binary fitting term introduced in the model as the local fitting term can efficiently deal with intensity inhomogeneity in images. Finally, we apply the Split Bregman method to minimize the proposed energy functional efficiently. The proposed model has been applied to segmentation of real medical and remote sensing images. Compared with other methods, the proposed model is superior in terms of both accuracy and efficient.     

面向嵌入式系统绿色需求的数据分配方法

能耗和资源等绿色需求是嵌入式系统发展不容忽视的因素.数据分配作为编译后端的重要优化手段,对能耗以及资源的利用率有着重要影响.为提高资源和能源的有效利用率,构建了数据分配过程的绿色评估模型,并以此为指导,提出了一种迭代式多目标分配优化方法,从能源消耗和资源的均衡使用度2个方面出发,利用可交换类指令重排优化和寄存器重分配优化,对总线和存储系统的绿色指标进行改进.模拟实验表明,该方法相对于GCC编译器,能够获得23％左右的绿色指标提升值,为满足更高的绿色需求提供了保障.     

基于CRF和规则相结合的地理命名实体识别方法

为了识别文本中海量的地理命名信息,以CRF(条件随机场)模型识别为基础,加入制定的规则,来提高CRF模型识别的召回率,从而提高整体的地理命名实体识别效果。通过选取适合的地理命名实体识别的特征模板,验证特征的有效性以及分析CRF模型识别结果中的未识别实体样本,设计针对未识别实体的规则用以修正识别结果。实验表明,对地名和组织名结合规则进行修正后的F值达到了91.61%和85.74%,有了显著提高。     

REST在异构移动客户端接入中的应用研究

针对繁多异构的移动客户端接入Web应用系统的问题,提出一个基于REST(Representational State Transfer)的解决方法并给出一个基于MVC(Model-View-Controller)模式的具体的开发框架,通过RESTful Web服务连接移动客户端的View/Controller层与Web系统的Model层。定义了由Web系统的model层定义RESTful Web服务的具体方法和规则。理论分析与实际应用说明了该方法的有效性。     

镀膜长周期光纤光栅透射谱研究

基于三包层长周期光纤光栅的耦合模型,研究了镀膜长周期光纤光栅的光栅参数和膜层厚度对长周期光纤光栅谐振波长的影响。研究发现,当长周期光纤光栅的纤芯半径、折射率和周期增大时,谐振波向长波方向漂移;当长周期光纤光栅的包层半径和折射率增大时,谐振波向短波方向漂移。不同折射率的膜层介质其所对应的最优厚度(Optimum Overlay Thickness,OOT)不同,薄膜介质的折射率越高,对应的最优厚度越小,敏感区域范围也较窄;不同包层模式对应的最优厚度具体位置区别不大,较高阶次包层模对应的谐振波长在敏感区域范围内漂移量较大。