网驰服务计算平台监测工具的设计与实现

Web服务作为面向服务计算范型的主要实现技术，能有效提高异构环境下分布式应用的开发效率，降低其开发成本。而Web服务应用系统的运行时质量保证及优化则可以通过采用监测机制实现。但是，由于Web服务具有高度的分布性、动态性，自主性等特点，Web服务应用系统的系统行为难以预期，这对Web服务应用的监测提出了很大的挑战。 论文首先分析了Web服务系统的监测需求，确定了Web服务QoS监测，流程运行时监测以及复合服务QoS评估三个方面的研究内容。在对以上问题进行深入分析的基础上，论文设计了一种基于监测事件时序图匹配的流程运行时监测方法。通过将BPEL流程转换成对应的监测事件时序图，并在运行时将监测事件与时序图进行动态匹配，解决了流程运行时监测中的监测事件展现乱序，流程执行路径难以确定等问题；通过综合考虑流程结构，流程执行历史信息和成员Web服务QoS，设计了一种复合服务QoS评估方法，能够对业务流程运行时动态服务绑定下的QoS进行评估，为业务流程的设计及运行时的服务选择提供了有力的依据。 最后论文基于网驰服务计算平台，设计和实现了服务计算平台监测工具，将前述研究成果引入其中。并通过在线旅游预订的应用案例，对监测工具进行了功能性测试。

BPEL流程监视的可视化实现

When a BPEL process is executed,it is necessary to dynamically monitor the process.BPEL is a executable language,which is not suitable for visual monitoring.On the other hand,BPMN is designed to visually describe business process and is more intuitive for monitoring.To visually monitor a BPEL process, transformation from BPEL to BPMN is necessary.However,current study of transformation from BPEL to BPMN does not support the transformation of"link"activity.Besides,no work has been done to add supplementary information into BPMN during transformation.In this paper,we transform nested BPEL process into a flat BPMN process graph without hierarchy through applying a flattening strategy.Especially, we analyze various scenarios of the transformation of link activity,and provide a method to deal with it. Besides,we analyze the mapping between BPEL activities and BPMN graph,through which we found out that some supplementary information cannot automatically obtained from BPEL process.These supplementary information need to be added during transformation.At the end of this paper,we present the structure of our monitoring tool which is based on our transformation algorithm.

Temperature and composition profile during double-track laser cladding of H13 tool steel

Multi-track laser cladding is now applied commercially in a range of industries such as automotive, mining and aerospace due to its diversified potential for material processing. The knowledge of temperature, velocity and composition distribution history is essential for a better understanding of the process and subsequent microstructure evolution and properties. Numerical simulation not only helps to understand the complex physical phenomena and underlying principles involved in this process, but it can also be used in the process prediction and system control. The double-track coaxial laser cladding with H13 tool steel powder injection is simulated using a comprehensive three-dimensional model, based on the mass, momentum, energy conservation and solute transport equation. Some important physical phenomena, such as heat transfer, phase changes, mass addition and fluid flow, are taken into account in the calculation. The physical properties for a mixture of solid and liquid phase are defined by treating it as a continuum media. The velocity of the laser beam during the transition between two tracks is considered. The evolution of temperature and composition of different monitoring locations is simulated.