On the basis of welding transformer circuit model, a new measuring method was proposed. This method measures the peak angle of the welding current, and then calculates the dynamic power factor in each half-wave. An ar...On the basis of welding transformer circuit model, a new measuring method was proposed. This method measures the peak angle of the welding current, and then calculates the dynamic power factor in each half-wave. An artificial neural network is trained and used to generate simulation data for the analytical solution, i.e. a high-order binary polynomial, which can be easily adopted to calculate the power factor online. The tailored sensing and computing system ensures that the method possesses a real-time computational capacity and satisfying accuracy. A DSP-based resistance spot welding monitoring system was developed to perform ANN computation. The experimental results suggest that this measuring method is feasible.展开更多
This paper studies the problem of deriving an interface automata model from UML statechart, in which, interface automata is a formaliged model for describing component behavior in an open system, but there is no unive...This paper studies the problem of deriving an interface automata model from UML statechart, in which, interface automata is a formaliged model for describing component behavior in an open system, but there is no universal criterion for deriving behavior from component to construct the model. UML is a widely used modeling standard, yet it is very difficult to apply it to system verification and testing directly for its imprecise semantics. After analyzing the expression ability of the two models, several transforma- tion rules are defined and each step of transformation is described in detail, after that, the approach is illustrated with an example. The paper provides a method for acquiring interface automata and lays the foundation for related research.展开更多
This work concerns the study of HSs （Hybrid Systems） that are made up of the integration of M-HTFC （Medium and High Temperature Fuel Cell） and MGT （Micro-Gas-Turbine）. Different typologies of hybrid systems are ...This work concerns the study of HSs （Hybrid Systems） that are made up of the integration of M-HTFC （Medium and High Temperature Fuel Cell） and MGT （Micro-Gas-Turbine）. Different typologies of hybrid systems are taken into account, which differ from each other in their plant layouts. The plants are considered in cogenerative arrangement. The aim of this study is to carry out an energetic analysis of the HS considered to obtain an analytical expression to depict the system operating in cogenerative arrangement. An energetic comparison among the systems analyzed based on some indexes is effected, which allows an evaluation of the plants performances in cogenerative arrangement. An energetic analysis is carried out, which is based on a ＂black box＂ depiction of the plant in which the components and the mutual interactions are highlighted. The fuel cell component of the plant is not analyzed as a black box, but each element that constitutes it, is elaborated as a subsystem.展开更多
This paper is organized as follows. After a discussion of the differential equations for wave propagation in the horizontally stratified medium and of the initial and boundary conditions, the displacements are derived...This paper is organized as follows. After a discussion of the differential equations for wave propagation in the horizontally stratified medium and of the initial and boundary conditions, the displacements are derived on the free surface of the layered medium for plane waves when a point source is located on the s-th imaginary boundary at the depth -s （physical parameters of the layers s and （s ＋ 1） are put to be identical）. Then, the source will be represented as a single force of arbitrary orientation and a general moment tensor point source. Further, ＂a primary field＂ for a point source will be introduced. Matrix method for the solution of the direct seismic problem is considered based on the matrix method of Thomson-Haskell and its modifications.展开更多
基金The National Natural Science Foundation of China (No 50575145)
文摘On the basis of welding transformer circuit model, a new measuring method was proposed. This method measures the peak angle of the welding current, and then calculates the dynamic power factor in each half-wave. An artificial neural network is trained and used to generate simulation data for the analytical solution, i.e. a high-order binary polynomial, which can be easily adopted to calculate the power factor online. The tailored sensing and computing system ensures that the method possesses a real-time computational capacity and satisfying accuracy. A DSP-based resistance spot welding monitoring system was developed to perform ANN computation. The experimental results suggest that this measuring method is feasible.
文摘This paper studies the problem of deriving an interface automata model from UML statechart, in which, interface automata is a formaliged model for describing component behavior in an open system, but there is no universal criterion for deriving behavior from component to construct the model. UML is a widely used modeling standard, yet it is very difficult to apply it to system verification and testing directly for its imprecise semantics. After analyzing the expression ability of the two models, several transforma- tion rules are defined and each step of transformation is described in detail, after that, the approach is illustrated with an example. The paper provides a method for acquiring interface automata and lays the foundation for related research.
文摘This work concerns the study of HSs （Hybrid Systems） that are made up of the integration of M-HTFC （Medium and High Temperature Fuel Cell） and MGT （Micro-Gas-Turbine）. Different typologies of hybrid systems are taken into account, which differ from each other in their plant layouts. The plants are considered in cogenerative arrangement. The aim of this study is to carry out an energetic analysis of the HS considered to obtain an analytical expression to depict the system operating in cogenerative arrangement. An energetic comparison among the systems analyzed based on some indexes is effected, which allows an evaluation of the plants performances in cogenerative arrangement. An energetic analysis is carried out, which is based on a ＂black box＂ depiction of the plant in which the components and the mutual interactions are highlighted. The fuel cell component of the plant is not analyzed as a black box, but each element that constitutes it, is elaborated as a subsystem.
文摘This paper is organized as follows. After a discussion of the differential equations for wave propagation in the horizontally stratified medium and of the initial and boundary conditions, the displacements are derived on the free surface of the layered medium for plane waves when a point source is located on the s-th imaginary boundary at the depth -s （physical parameters of the layers s and （s ＋ 1） are put to be identical）. Then, the source will be represented as a single force of arbitrary orientation and a general moment tensor point source. Further, ＂a primary field＂ for a point source will be introduced. Matrix method for the solution of the direct seismic problem is considered based on the matrix method of Thomson-Haskell and its modifications.
