凹域 meaning in English

concave region

Based on the search - extend - method ( sem ) that proposed by c . m . chen and z . q . xie for computing multiple solutions of nonlinear elliptic equation , this paper introduces the fem and the interpolated coefficient finite element method into the sem and calls this improved version as isem . isem not only can reduce our expensive computation greatly but also can be generalized to non - odd nonlinearity cases as well as many different domains ( including the concave domains )
本文在c . m . chen和z . q . xie提出的一种全新的计算非线性椭圆型方程多解的搜寻延拓方法sem的基础上，引入了有限元方法和插值系数方法，改进后的sem (称为isem )大大减少了计算量，并且将原方法推广到非奇非线性情形和多种区域(包括凹域)上。