This paper presents and proves the mixed compatible finite element variationalprinciples in dynamics of viscous barotropic fluids. When the principles are proved, itis found that the compatibility conditions of stress...This paper presents and proves the mixed compatible finite element variationalprinciples in dynamics of viscous barotropic fluids. When the principles are proved, itis found that the compatibility conditions of stress can be naturally satisfied. The gene-rallzed variational principles with mixed hybrid incompatible finite elements are alsopresented and proved, and they can reduce the computation of incompatible elements indynamics of viscous barotropic flows.展开更多
The quadrilateral discrete Kirchhoff thin plate bending element DKQ is based on the isoparametric element Q8, however, the accuracy of the isoparametric quadrilateral elements will drop significantly due to mesh disto...The quadrilateral discrete Kirchhoff thin plate bending element DKQ is based on the isoparametric element Q8, however, the accuracy of the isoparametric quadrilateral elements will drop significantly due to mesh distortions. In a previous work, we constructed an 8-node quadrilateral spline element L8 using the triangular area coordinates and the B- net method, which can be insensitive to mesh distortions and possess the second order completeness in the Cartesian co- ordinates. In this paper, a thin plate spline element is devel- oped based on the spline element L8 and the refined tech- nique. Numerical examples show that the present element indeed possesses higher accuracy than the DKQ element for distorted meshes.展开更多
With the vehement development of global competition , Agile Supply Chain (ASC) becomes an effective approach that supports dynamic ent erprise alliance and realizes agile manufacturing, as for the enterprises to cap t...With the vehement development of global competition , Agile Supply Chain (ASC) becomes an effective approach that supports dynamic ent erprise alliance and realizes agile manufacturing, as for the enterprises to cap ture market opportunities rapidly and strengthen their anti-risk ability. As Ag ile Supply Chain System (ASCS) is dynamic and distributed, the realization of it ’s processes needs to be much flexible. Often in Agile Supply Chain System (ASCS ), there are many dynamic tasks, many changes of the processes, and cooperative workflows, which need the workflows able to be adjusted agilely and smoothly, no t much affecting others. This paper will propose a flexible workflow management for achieving the agility and compatibility. At the first of the paper, we will discuss the situation in which Agile Supply C hain System is applied, and then we will elaborate the characteristics of Agile Supply Chain System. So with that, the shortcomings of the process managements t hat are, at present, used in Supply Chain Systems will be displayed clearly. The n, the proposal will be given in the paper, to resolve the problems in the prese nt process management in ASCS. We will see supply chain systems implemented mult i-agent-based technology to adapt to the dynamic environment, however in many systems, coordination of the workflows is executed by the explicit messages comm unicated between the agents. This will lead to a tightly coupled system. To over come it, the paper suggests the workflow management in agent-based ASCS using t he Events-Triggering mechanism, instead of the explicit messages. We create Eve nts-Triggering contents and rules, having push-pull mechanism, event-state se t and triggering-conditions, and store them in the distributed database subject ed to the corresponding agents. Adjusting the Events-Triggering data will be us ed to adapt to the dynamic tasks and the changes of processes. In sum, we will p resent the methods of process modeling, the system structure, and the executing -mechanism of the flexible workflow management we propose in the paper. Also, t he paper outlines several exception-handling policies for the flexible workflow management, in succession. And at the final of the paper, we discuss the realiz ation of the flexible workflow management in Agile Supply Chain System. The flex ible workflow management will be implemented using CORBA services and Java techn ology for the distributed systems. CORBA is chosen as the specification of distr ibuted electronic data exchange, and Java as the construction tool of the system . The framework of the flexible workflow management constructed on them is showe d in the paper.展开更多
This paper focused on the evolution over time of elasticity of the cement paste during the hydration, e g, Young＇s modulus and Poisson＇s ration, by the proposed homogenization method combined the percolation algorit...This paper focused on the evolution over time of elasticity of the cement paste during the hydration, e g, Young＇s modulus and Poisson＇s ration, by the proposed homogenization method combined the percolation algorithm with individual phase intrinsic elasticity. A cement paste development model, named CEMHYD3D, was used to establish an accurate microstructure. The modelling results are in good agreement with the experimental data and other numerical results available in the open literatm＇e. The suitable homogeneous scheme, applied to each level, should be carefully chosen to result in a realistic prediction. The percolation concept should aims to correctly predict the elasticity for cement paste at very early age, especially under low w/c ratios.展开更多
随着工业自动化水平的不断提高,多电机协同驱动系统在生产线、智能制造等领域应用日益广泛。针对传统变频器调试方法中存在的接线复杂、地址冲突、效率低下及管理不便等问题,本文提出了一种基于CAN(Controller Area Network)总线的变频...随着工业自动化水平的不断提高,多电机协同驱动系统在生产线、智能制造等领域应用日益广泛。针对传统变频器调试方法中存在的接线复杂、地址冲突、效率低下及管理不便等问题,本文提出了一种基于CAN(Controller Area Network)总线的变频器集中调试方法。通过上位机对网络中所有变频器的CAN ID偏移值进行统一管理、自动校验、数据库存储与读取,并基于此实现精准的报文发送与筛选处理。渡锌生产线现场应用表明,该方法能够显著提高多变频器系统的调试效率,降低人为操作错误,增强系统的可维护性与可扩展性,为工业现场的设备调试提供了一种高效、可靠的解决方案。展开更多
文摘This paper presents and proves the mixed compatible finite element variationalprinciples in dynamics of viscous barotropic fluids. When the principles are proved, itis found that the compatibility conditions of stress can be naturally satisfied. The gene-rallzed variational principles with mixed hybrid incompatible finite elements are alsopresented and proved, and they can reduce the computation of incompatible elements indynamics of viscous barotropic flows.
基金supported by the National Natural Science Foundation of China(11001037,11102037,11290143)the Fundamental Research Funds for the Central Universities(DUT13LK07)
文摘The quadrilateral discrete Kirchhoff thin plate bending element DKQ is based on the isoparametric element Q8, however, the accuracy of the isoparametric quadrilateral elements will drop significantly due to mesh distortions. In a previous work, we constructed an 8-node quadrilateral spline element L8 using the triangular area coordinates and the B- net method, which can be insensitive to mesh distortions and possess the second order completeness in the Cartesian co- ordinates. In this paper, a thin plate spline element is devel- oped based on the spline element L8 and the refined tech- nique. Numerical examples show that the present element indeed possesses higher accuracy than the DKQ element for distorted meshes.
文摘With the vehement development of global competition , Agile Supply Chain (ASC) becomes an effective approach that supports dynamic ent erprise alliance and realizes agile manufacturing, as for the enterprises to cap ture market opportunities rapidly and strengthen their anti-risk ability. As Ag ile Supply Chain System (ASCS) is dynamic and distributed, the realization of it ’s processes needs to be much flexible. Often in Agile Supply Chain System (ASCS ), there are many dynamic tasks, many changes of the processes, and cooperative workflows, which need the workflows able to be adjusted agilely and smoothly, no t much affecting others. This paper will propose a flexible workflow management for achieving the agility and compatibility. At the first of the paper, we will discuss the situation in which Agile Supply C hain System is applied, and then we will elaborate the characteristics of Agile Supply Chain System. So with that, the shortcomings of the process managements t hat are, at present, used in Supply Chain Systems will be displayed clearly. The n, the proposal will be given in the paper, to resolve the problems in the prese nt process management in ASCS. We will see supply chain systems implemented mult i-agent-based technology to adapt to the dynamic environment, however in many systems, coordination of the workflows is executed by the explicit messages comm unicated between the agents. This will lead to a tightly coupled system. To over come it, the paper suggests the workflow management in agent-based ASCS using t he Events-Triggering mechanism, instead of the explicit messages. We create Eve nts-Triggering contents and rules, having push-pull mechanism, event-state se t and triggering-conditions, and store them in the distributed database subject ed to the corresponding agents. Adjusting the Events-Triggering data will be us ed to adapt to the dynamic tasks and the changes of processes. In sum, we will p resent the methods of process modeling, the system structure, and the executing -mechanism of the flexible workflow management we propose in the paper. Also, t he paper outlines several exception-handling policies for the flexible workflow management, in succession. And at the final of the paper, we discuss the realiz ation of the flexible workflow management in Agile Supply Chain System. The flex ible workflow management will be implemented using CORBA services and Java techn ology for the distributed systems. CORBA is chosen as the specification of distr ibuted electronic data exchange, and Java as the construction tool of the system . The framework of the flexible workflow management constructed on them is showe d in the paper.
基金Funded by the National Natural Science Foundation of China(No.51279054)
文摘This paper focused on the evolution over time of elasticity of the cement paste during the hydration, e g, Young＇s modulus and Poisson＇s ration, by the proposed homogenization method combined the percolation algorithm with individual phase intrinsic elasticity. A cement paste development model, named CEMHYD3D, was used to establish an accurate microstructure. The modelling results are in good agreement with the experimental data and other numerical results available in the open literatm＇e. The suitable homogeneous scheme, applied to each level, should be carefully chosen to result in a realistic prediction. The percolation concept should aims to correctly predict the elasticity for cement paste at very early age, especially under low w/c ratios.
文摘随着工业自动化水平的不断提高,多电机协同驱动系统在生产线、智能制造等领域应用日益广泛。针对传统变频器调试方法中存在的接线复杂、地址冲突、效率低下及管理不便等问题,本文提出了一种基于CAN(Controller Area Network)总线的变频器集中调试方法。通过上位机对网络中所有变频器的CAN ID偏移值进行统一管理、自动校验、数据库存储与读取,并基于此实现精准的报文发送与筛选处理。渡锌生产线现场应用表明,该方法能够显著提高多变频器系统的调试效率,降低人为操作错误,增强系统的可维护性与可扩展性,为工业现场的设备调试提供了一种高效、可靠的解决方案。
