In this paper two classes of equivalence transform methods for solving ordinary differential equations are proposed. One class of method is the equivalence integral transform method for special differential algebraic ...In this paper two classes of equivalence transform methods for solving ordinary differential equations are proposed. One class of method is the equivalence integral transform method for special differential algebraic problems. The advantage of this class of method is such that the amount of work calculating one integration with parameters becomes that of two interpolations, when the system of nonlinear equations is solved on the right hand side function. The other class of method is the equivalence substitution method for avoiding calculating derivative on the right hand side function. In order to avoid calculation derivatives, two equivalence substitution methods are proposed here. The application instances of some special effect of the equivalence substitution methods are given.展开更多
It is important but difficult to analyze the electromagnetic environment effect(E3) in the designing of modern airborne,sea,space,and ground systems.Thus a hybrid algorithm of time domain integral equation,finite diff...It is important but difficult to analyze the electromagnetic environment effect(E3) in the designing of modern airborne,sea,space,and ground systems.Thus a hybrid algorithm of time domain integral equation,finite difference time domain and modified nodal analysis(TDIE-FDTD-MNA) is developed to analyze the E3 of complex systems with cables and nonlinear circuit structures.The plane wave time domain(PWTD) enhanced TDIE method is adopted to solve field problems.The higher order FDTD(2,4) is adopted to solve cable problems.The MNA is adopted to obtain the response of complex circuits(with nonlinear structures).Numerical examples demonstrate the effectiveness of the proposed algorithm.展开更多
提出一种新型降雨反演算法,该算法是对沃尔塔积分方程(Volterra integral equation,VIE)降雨反演算法的改进.首先,对雷达接收到的回波数据进行预处理,得到降雨起点和降雨宽度等信息;然后,仅利用沃尔塔积分反演算法处理少量特定区域,通...提出一种新型降雨反演算法,该算法是对沃尔塔积分方程(Volterra integral equation,VIE)降雨反演算法的改进.首先,对雷达接收到的回波数据进行预处理,得到降雨起点和降雨宽度等信息;然后,仅利用沃尔塔积分反演算法处理少量特定区域,通过深度挖掘数据变化的规律来分析得出降雨分布的类型和降雨速率;最后,根据通常研究对象的分布对称性,结合已经获得的信息反演得到整个区域的降雨分布情况.通过仿真结果可知,该算法高效、计算速度快,并且具有较高的精度.展开更多
基金The project was supported by the National Natural Science Faundation of China
文摘In this paper two classes of equivalence transform methods for solving ordinary differential equations are proposed. One class of method is the equivalence integral transform method for special differential algebraic problems. The advantage of this class of method is such that the amount of work calculating one integration with parameters becomes that of two interpolations, when the system of nonlinear equations is solved on the right hand side function. The other class of method is the equivalence substitution method for avoiding calculating derivative on the right hand side function. In order to avoid calculation derivatives, two equivalence substitution methods are proposed here. The application instances of some special effect of the equivalence substitution methods are given.
基金supported by National Basic Research Program of China(973 Program)
文摘It is important but difficult to analyze the electromagnetic environment effect(E3) in the designing of modern airborne,sea,space,and ground systems.Thus a hybrid algorithm of time domain integral equation,finite difference time domain and modified nodal analysis(TDIE-FDTD-MNA) is developed to analyze the E3 of complex systems with cables and nonlinear circuit structures.The plane wave time domain(PWTD) enhanced TDIE method is adopted to solve field problems.The higher order FDTD(2,4) is adopted to solve cable problems.The MNA is adopted to obtain the response of complex circuits(with nonlinear structures).Numerical examples demonstrate the effectiveness of the proposed algorithm.
文摘提出一种新型降雨反演算法,该算法是对沃尔塔积分方程(Volterra integral equation,VIE)降雨反演算法的改进.首先,对雷达接收到的回波数据进行预处理,得到降雨起点和降雨宽度等信息;然后,仅利用沃尔塔积分反演算法处理少量特定区域,通过深度挖掘数据变化的规律来分析得出降雨分布的类型和降雨速率;最后,根据通常研究对象的分布对称性,结合已经获得的信息反演得到整个区域的降雨分布情况.通过仿真结果可知,该算法高效、计算速度快,并且具有较高的精度.
