论焊接结构生产的技术改造

本文讨论了焊接结构生产技术改造的有关问题，包括总思路及总目标、自动化的基本框架、按低成本自动化的原则设计生产线和关键技术问题的论述。     

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.     

基于自编码神经网络建立的搜索信息模型

根据用户搜索历史,将用户关注的信息按标题分类,通过自编码神经网络提取特征值。设定学习样本标题最多为25个汉字,编码方式采用汉字机内码(GBK码)。使用 MATLAB工具进行深度学习,将样本在原空间的特征表示变换到一个新的特征空间。     

Image processing acceleration for intelligent unmanned aerial vehicle on mobile GPU

In this paper, we present an algorithm for providing visually-guided unmanned aerial vehicle (UAV) control using visual information that is processed on a mobile graphic processing unit (GPU). Most real-time machine vision applications for UAVs exploit low-resolution images because the shortage of computational resources comes from size, weight and power issue. This leads to the limitation that the data are insufficient to provide the UAV with intelligent behavior. However, GPUs have emerged as inexpensive parallel processors that are capable of providing high computational power in mobile environments. We present an approach for detecting and tracking lines that use a mobile GPU. Hough transform and clustering techniques were used for robust and fast tracking. We achieved accurate line detection and faster tracking performance using the mobile GPU as compared with an x86 i5 CPU. Moreover, the average results showed that the GPU provided approximately five times speedup as compared to an ARM quad-core Cortex-A15. We conducted a detailed analysis of the performance of proposed tracking and detection algorithm and obtained meaningful results that could be utilized in real flight.     

Output performance optimization for RTD fluxgate sensor based on dynamic permeability基于动态磁导率参数的时间差型磁通门传感器的输出响应优化

The output performance of residence times difference (RTD) fluxgate may vary under different driving conditions (driving currents and frequencies) and core materials. To optimize the RTD fluxgate and simplify its design process, an analytical model is employed to select the parameters and identify the effective factors that dominate the performance. The dynamic permeability parameters (P_i), which reflect the changes in the magnetization curve, are mathematically analyzed in detail. The linear variation functions of P_i in different driving conditions are fitted by using the dynamic arctangent hysteresis model. Consequently, the selection of driving conditions and core materials, which are assessed by comparing the experiment and simulation results, has an important role in achieving the optimal output performance of the RTD fluxgate.     

大数据时代对高校人才培养模式的影响——以信息系统专业为例

大数据具有数据量巨大、数据形式多样化等特点,大数据时代为教育和学习提供了丰富的信息资源,但也给教育模式和人才培养带来挑战。首先具体说明大数据时代的特点及对高校人才培养的影响,分析大数据时代对信息系统及相应人才的要求,结合教学实践研究大数据背景下信息系统专业的人才培养模式。     

基于离散粒子群算法全局QoS最优的Web服务选择

Web服务选择是Web服务组合中重要问题,也是一个NP难问题,使用离散粒子群算法对该问题进行建模求解并针对粒子群算法后期容易陷入局部最优进行改进,借鉴遗传算法中杂交变异的思想对算法迭代后期的一部分粒子进行杂交变异,实验仿真证明,由于杂交变异的引入,能够求得Web服务组合全局QoS更优的解。     

Complete controllability for abstract measure differential systems

In this paper, we investigate the complete controllability for abstract measure differential systems. Firstly, we introduce several new concepts about complete controllability for abstract measure differential systems. Then, on the basis of the Sadovskii fixed‐point theorem, we give sufficient conditions for complete controllability for a class of abstract measure differential systems. The compactness of the semigroup generated by some operator is unnecessary in this paper, and we show that our results, dealing with complete controllability problem for an ordinary differential system in infinite‐dimensional Banach space, are also less conservative than that in the previous literature. Copyright © 2012 John Wiley & Sons, Ltd.     

A study of optimal viewing distance in a parallax barrier 3D display

The optimal viewing distance was proposed as a parameter for designing a parallax barrier 3D display. It can be designed based on simple geometric method and by considering the pitches of image display pixels and parallax barrier, or even including the aperture ratios of the image display pixels and parallax barrier. It can be analyzed by using ray tracing method. By considering the optical refraction index of the cover glass, the angular behavior of the system becomes more realistic; however, the geometric method is difficult to be used. We propose a revised method for estimating the view distance and angular behavior. In this paper, we have demonstrated a designated eye position (DEP) for each view and shown that multiple DEPs make a circular curve around the center of the display. We prove the new concept by comparing the optical ray tracing calculations and optical measurement.