材料氢脆涡流评价的有限元仿真研究*

针对扩散氢在材料内部渗透和聚集引起的氢脆问题,提出了一种基于涡流信号的表征方法。以电化学充氢试样为研究对象,首先基于Fick定律计算了电化学充氢过程中试样的氢分布,然后基于电磁感应原理运用COMSOL Multiphysics建立了不同氢分布状态下材料氢脆的涡流检测有限元模型,通过数值计算分析时谐电磁场激励下试样的感生涡流场分布及检测线圈的电磁场量图,并通过原位拉伸实验定量表征氢脆程度,最后分析了氢脆指数-涡流响应信号之间的关联机制,进行实验验证。研究结果表明,金属材料的氢脆程度与所含氢含量密切相关,时谐电磁场作用下的涡流信号与氢脆程度呈现线性相关,验证了材料氢脆涡流评价的有限元模型的有效性。     

Trends in intelligent manufacturing research: a keyword co-occurrence network based review

Journal of Intelligent Manufacturing - In recent years, driven by Industry 4.0 wave, academic research has focused on the science, engineering, and enabling technologies for intelligent and cyber...     

基于对抗深度学习的无人机航拍违建场地识别

对违建场地的检测方法主要是通过人工对无人机航拍视频进行检查,存在检测精度低、识别性能差、工作效率低的问题。提出一种结合空间变换网络与Fast RCNN的生成对抗网络ASTN-Fast RCNN,通过深度学习与无人机航拍视频相结合自动识别检测处在建设初期的违建场地。将空间变换网络作为生成器,生成Fast RCNN目标检测器难以识别的旋转形变样本,并通过目标检测器与生成器的对抗式训练,提高检测器的鲁棒性。实验结果表明,该方法能够有效提高对无人机航拍违建场地的识别性能。     

小兴安岭7种松叶挥发油GC-MS数据的分析

用化学计量学方法分析小兴安岭7种松科植物松叶挥发油气相色谱-质谱(GC-MS)数据,为松叶挥发油的药理活性与其它的应用研究提供依据。(1)用直观推导式演进特征投影(heuristic evolving latent projections,HELP)法分辨重叠色谱峰,得各组分的纯色谱峰和质谱;(2)用正交投影法比较不同挥发油的GC-MS数据;(3)用峰面积归一化法确定各化合物的相对含量;(4)用主要化学成分进行聚类分析。7种松叶挥发油的化学成分为单萜、倍半萜及其衍生物和酯类化合物,按化学成分7种松叶挥发油可分为3类。     

Recursive segmentation and recognition templates for image parsing

In this paper, we propose a Hierarchical Image Model (HIM) which parses images to perform segmentation and object recognition. The HIM represents the image recursively by segmentation and recognition templates at multiple levels of the hierarchy. This has advantages for representation, inference, and learning. First, the HIM has a coarse-to-fine representation which is capable of capturing long-range dependency and exploiting different levels of contextual information (similar to how natural language models represent sentence structure in terms of hierarchical representations such as verb and noun phrases). Second, the structure of the HIM allows us to design a rapid inference algorithm, based on dynamic programming, which yields the first polynomial time algorithm for image labeling. Third, we learn the HIM efficiently using machine learning methods from a labeled data set. We demonstrate that the HIM is comparable with the state-of-the-art methods by evaluation on the challenging public MSRC and PASCAL VOC 2007 image data sets.     

Automatic Real-Time Video Matting Using Time-of-Flight Camera and Multichannel Poisson Equations

This paper presents an automatic real-time video matting system. The proposed system consists of two novel components. In order to automatically generate trimaps for live videos, we advocate a Time-of-Flight (TOF) camera-based approach to video bilayer segmentation. Our algorithm combines color and depth cues in a probabilistic fusion framework. The scene depth information returned by the TOF camera is less sensitive to environment changes, which makes our method robust to illumination variation, dynamic background and camera motion. For the second step, we perform alpha matting based on the segmentation result. Our matting algorithm uses a set of novel Poisson equations that are derived for handling multichannel color vectors, as well as the depth information captured. Real-time processing speed is achieved through optimizing the algorithm for parallel processing on graphics hardware. We demonstrate the effectiveness of our matting system on an extensive set of experimental results.     

基于RFID和GPRS的远程监控系统设计与实现

针对目前监控系统监测点分散、数量大、信息统计难的问题,提出了一种基于射频识别(RFID)技术和GPRS技术的远程监控系统,进行了系统的总体设计,给出了详细的手持读写器硬件和软件设计,主要包括射频读写模块、GPRS模块、主控制器模块等。射频读写模块采集数据后,通过GPRS模块将数据上传至上位机进行分类管理,实现了监控系统自动化,提高了管理效率。整个系统采用锂电池供电,成本低,使用方便,安全可靠。