大型问题 meaning in English

large scale problem
large-scale problem

We know that the convergence rate is related to lk , uk according to the previous study , t
变得越来越大时，上面两个问题为大型问题且其hesse矩阵为稀疏矩阵。
Steihaug has shown that an approximate solution of the trust region problem may be found by the pcg method
共轭梯度法由于不需要矩阵计算和存贮，成了解大型问题的首选方法。
Vsp is a typical strong np - hard problem , high effective exact algorithm is immposible to it . heuristic algorithm can resolve large - scale problem , but cannot ensure the quality of the resolution
Vsp是一个典型的np -难题，高效的精确算法存在的可能性不大，启发式算法虽能快速求解大型问题，但对解的质量没有保证。
The main innovation of this article is aiming at the particularity of seismic records , brings forward one improved algorithmic of computing the multi - fractals spectrum and the speed of computing being quickened consumedly , so making the algorithmic adapting the computing of large - scale question about the oil & gas forecast of three - dimensional seismic records
本文的主要创新在于针对地震记录的特殊性提出了一种多重分形谱的改进算法，大大提高了计算速度，使得该算法能适应三维地震资料油气预测这样的大型问题的计算。