Auto_Regression

ABAQUS中用户材料子程序UMAT的开发主要解决两方面的问题：本构模型的建立和积分算法的选择。 本文主要研究非线性材料的UMAT实现方法，并重点研究其迭代算法部分，目前，用户材料子程序UMAT的迭代算法主要是常刚度法，常刚度法的优点在于算法原理较简单，程序编写较方便，缺点是当遇到复杂非线性材料时，其迭代次数较多，收敛速度也较慢，在这个情况下，本文采取的是一种迭代次数较少且收敛速度较快的切线刚度法，具体就是采用FORTRAN语言编制了基于Von-Mises模型的接口程序,并采用切线刚度算法，通过与ABAQUS自带本构关系计算的结果相比较，验证其正确性。(This paper studies the user subroutine UMAT of ABAQUS development methods, the use of FORTRAN language isotropic hardening material model of the interface program, studied the effects of such material is extremely elastic-plastic constitutive relation method. This article UMAT tightly around the secondary development of technology, the first principle of its interface detail, and then for the theory of nonlinear finite element incremental stiffness of the regular tangent stiffness method and the theory of algorithms to do an in-depth analysis of deduced a regular tangent stiffness and rigidity of the law of the specific expression of algorithm theory, and then the preparation of the two algorithms, respectively, of the UMAT program, and finally the establishment of a specific model checking, bringing with ABAQUS elasto-plastic constitutive relation of the calculated results compared to verify the correctness of the two.)

处理任意两点间多条公交、地铁线路的到达问题此，改程序将一二问综合在一起，方便精简，运行速度快(Treatment between any two many bus, subway lines to reach this issue, change the program integrated with the twelve asked to facilitate streamlined, fast)

用于生成空气动力学力学计算中的计算O型网格(generate the calculational grid)

说明：  MATLAB的一个使用工具箱，LINGO11汉化无限变量版。(A toolbox of MATLAB, LINGO11 Chinese Infinite Variable Edition.)

在VS2005环境下，使用CUDA编程实现SAR成像中CSA算法的实现，得到了很好的加速比。(In the VS2005 environment, using the CUDA programming SAR imaging algorithm implementation in the CSA, has been very good speedup.)

说明：  用混合同余法生成两组伪随机数，利用投针试验求圆周率。软件：matlab。(Two groups of pseudo-random numbers are generated by the method of mixed congruence, and the circularity is calculated by the test of inserting needle. Software: MATLAB.)

求解速度压力耦合的Simple半隐式迭代方法，该方法在计算流体动力学中应用极为广泛(To solve the pressure velocity coupling Simple semi-implicit iterative method, the method applied in the Computational Fluid Dynamics an extremely wide range of)

插值与拟合，牛顿插值法，直接利用拉格朗日插值多项式的病态性(Interpolation and fitting, Newton interpolation method, the direct use of Lagrange Interpolation polynomial morbid)

很有用的一篇国外关于FDTD算法的学术论文，相信对初学者有很大帮助(Useful in a foreign academic papers on the FDTD method, I believe very helpful for beginners)

可进行最小二乘法线性拟合输出，包含源代码及生成后的程序(Least-squares linear fit can be output)