Workflow management systems are widely used in improving the efficiency of business processes. To develop a workflow management system is the key to workflow modeling. In this paper, the compositional time net is presented to model workflow processes on the basis of the analyzing methods of time Petri nets and workflows, and to describe the static relationships and the dynamic semantics of the task of multiple workflow com- position. The paper puts more emphasis on checking the sotmdness of composed workflow, at the same time, combinational problems of non-conditional structure of the compositional time net are introduced and analyzed. A sufficient and necessary condition for determining the soundness of compositional nets is obtained.
随着现代通信带宽的日益提高,图像处理技术在计算机技术领域的成熟,人们对视频的实时传输和采集提出了速度越快、成本越低的需求。以ARM和嵌入式Linux系统为实验环境,通过V4L2进行视频采集,运用x264进行视频压缩,根据RTP协议对视频流信息进行打包。通过UDP传送,VLC media player作为客户端播放,设计并实现了一个实时视频监控系统。
