本书通过深入分析现有复杂决策问题的特征，在检索大量外资料，跟踪国际前沿技术的基础上，应用多学科交叉技术，将粗糙集理论引入经典的多属性决策方法中，并将管理学、人工智能、信息科学等知识相融合。在系统观点指导下，针对经典多属性决策方法中存在的严格假设问题，重点研究了粗糙集属性约简理论、粗集分类、奇异粗集等理论在经典的多属性决策理论与方法，最后经过模拟、试验和算例验证了该方的有效性，具有重要的理论意义和应用价值。 本书可作为高等院校运筹学、管理科学、信息科学和系统工程专业的研究生教材，也可作为相关领域研究人员、工程技术人员、管理干部、教师和学者的参考书。
The book is a continuation of development of" Boundary value problems for nonlinear elliptic equations and systems" and "Linear and quasilinear equations of hyperbolic and mixed types ".A large portion of the work is devoted to boundary value problems for general elliptic plex equations of first,second and fourth order,initial-boundary value problems for nonlinear parabolic plex equations of first and second order.Moreover,some results about first and second order plex equations of mixed (elliptic-hyperbolic) type are investigated .Applications of nonlinear plex analysis to continuum mechanics are also introduced.
